Premium Essay

Submitted By perfectsquare

Words 1906

Pages 8

Words 1906

Pages 8

Due Date: Hardcopy to be handed in at the lecture on Friday 9th December.

Answer all the questions.Write your answers using a pen and paper.Graph paper is available. Each question is worth 10 marks.

1. Purchases (to the nearest dollar) made at a café by each of the first 40 customers were as follows: 15 | 7 | 33 | 25 | 42 | 15 | 6 | 19 | 7 | 18 | 8 | 48 | 51 | 6 | 52 | 48 | 56 | 36 | 52 | 29 | 21 | 50 | 12 | 54 | 18 | 9 | 8 | 4 | 52 | 14 | 18 | 48 | 25 | 47 | 20 | 3 | 48 | 16 | 42 | 23 |

Use these data to construct:

a) A frequency distribution Class limit | frequency | 3-11 | 9 | 12-20 | 10 | 21-29 | 5 | 30-38 | 2 | 39-47 | 3 | 48-56 | 11 | total | 40 |

b) A cumulative frequency distribution

Class limit | frequency | Commulative frequency | 3-11 | 9 | 9 | 12-20 | 10 | 19 | 21-29 | 5 | 24 | 30-38 | 2 | 26 | 39-47 | 3 | 29 | 48-56 | 11 | 40 | total | 40 | |

c) A grouped frequency distribution with class intervals of length $10

Class limit | frequency | Commulative frequency | 3-12 | 10 | 10 | 13-22 | 10 | 20 | 23-32 | 4 | 24 | 33-42 | 4 | 28 | 43-52 | 10 | 38 | 53-62 | 2 | 40 | total | 40 | |

d) A histogram

e) A frequency polygon.

2. Among 20 applicants for a position in a stockbroking firm, there are 6 who have tertiary qualifications and 2 with professional accountancy qualifications. If three of the applicants are chosen at random for interview, find the probability that:

a) None of them has tertiary or accountancy qualifications

Total applicants =20

Tertiary qualifications=6

Accountancy =2

Selected=3

P(None of them has tertiary or accountancy qualifications)

P(A)=6C0*2C0*12C3/20C3

=1*1*220/1140

= 0.192982

b) All three of them have tertiary or professional…...

Premium Essay

...This paper will explain what statistics are. Statistics are used in so many ways, including business. This paper will thoroughly defining statistics, the types and levels of statistics, the role of statistics in a business and examples of how statistics may be used. The most common definition for statistics would be the collection of numerical data. Examples of numerical data could be the percentage of how many African-Americans passed, dropped out or failed out of high school in Vallejo, CA in 2013. Another would be how many slam dunks did LeBron James have last year or asking how many assist did LeBron James average last season; would give you numerical data. In this coarse, statistics is described as the science of collecting, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions. Statistics are usually divided into two catagories, descriptive and inferential statistics. Discriptive statistics are the methods of organizing, summarizing and presenting data in an informative way. Inferential statistics (also known as statistical inference) are the methods used to estimate a property of a population on the basis of a sample. There are two variables/attributes involved in statistics, qualitative and quantitative. Qualitative variables are when the characteristics being studied are categorical or nonnumeric. Quantitative variables are when a variable is studied and the study describes how much or how many. There are four......

Words: 563 - Pages: 3

Premium Essay

... Cases Used All non-missing data are used. Syntax DESCRIPTIVES VARIABLES=Income /STATISTICS=MEAN STDDEV VARIANCE RANGE MIN MAX SKEWNESS. Resources Processor Time 00:00:00.00 Elapsed Time 00:00:00.02 [DataSet0] Descriptive Statistics N Range Minimum Maximum Mean Std. Deviation Statistic Statistic Statistic Statistic Statistic Statistic Three-Year-Average Median Income(2008-2010) 51 $29,453 $36,850 $66,303 $50,734.18 $7,555.310 Valid N (listwise) 51 Descriptive Statistics Variance Skewness Statistic Statistic Std. Error Three-Year-Average Median Income(2008-2010) 57082705.308 .389 .333 Valid N (listwise) EXAMINE VARIABLES=Income /PLOT BOXPLOT STEMLEAF /COMPARE GROUPS /PERCENTILES(5,10,25,50,75,90,95) HAVERAGE /STATISTICS DESCRIPTIVES EXTREME /CINTERVAL 95 /MISSING LISTWISE /NOTOTAL. Explore Notes Output Created 05-SEP-2012 16:32:55 Comments Input Active Dataset DataSet0 Filter Weight Split File N of Rows in Working Data File 51 Missing Value Handling Definition of Missing User-defined missing values for dependent variables are treated as missing. Cases Used Statistics are based on cases with no missing values for any dependent variable or factor used. Syntax EXAMINE VARIABLES=Income /PLOT BOXPLOT STEMLEAF /COMPARE GROUPS /PERCENTILES(5,10,25,50,75,90,95) HAVERAGE /STATISTICS DESCRIPTIVES EXTREME /CINTERVAL 95 /MISSING LISTWISE ......

Words: 519 - Pages: 3

Premium Essay

...Descriptive and Inferential Statistics ________________________________________ Statistics can be broken into two basic types. The first is known as descriptive statistics. This is a set of methods to describe data that we have collected. Ex. Of 350 randomly selected people in the town of Luserna, Italy, 280 people had the last name Nicolussi. An example of descriptive statistics is the following statement : "80% of these people have the last name Nicolussi." Ex. On the last 3 Sundays, Henry D. Carsalesman sold 2, 1, and 0 new cars respectively. An example of descriptive statistics is the following statement : "Henry averaged 1 new car sold for the last 3 Sundays." These are both descriptive statements because they can actually be verified from the information provided. The second type of statistics in inferential statistics. This is a set of methods used to make a generalization, estimate, prediction or decision. Ex. Of 350 randomly selected people in the town of Luserna, Italy, 280 people had the last name Nicolussi. An example of inferential statistics is the following statement : "80% of all people living in Italy have the last name Nicolussi." We have no information about all people living in Italy, just about the 350 living in Luserna. We have taken that information and generalized it to talk about all people living in Italy. The easiest way to tell that this statement is not descriptive is by trying to verify it based upon the information provided. Ex....

Words: 2703 - Pages: 11

Premium Essay

...determine if the data are distributed normally. The Histogram below as well as the Descriptive Statistics (Appendix 1, Table 1b) show that the data distribution is leptokurtic (kurtosis is 2,021) and negatively skewed (skewness -,240). We can determine several outliers (Appendix 1, Table 1c, Table 1d) with extreme ratios. In cases #46 and #178 JSL is more than the highest option provided in the questionnaire. That could be a mistake in data entering or the respondent wanted to emphasise his/her satisfaction level. These cases were delisted. Cases with “0” responses are to be excluded from the further analysis as irrelevant data too. After the data revision there are 194 cases left in the dataset. Although the distribution is still negativeley skewed we may observe the distribution is closer to normal in terms of kurtosis. (Appendix 2, Picture 1a, Table 1c). We checked the significance of non normal distribution by comparing the numeric value of kurtosis with twice the Std. Error of kurtosis. Looking at the range from minus twice the Std.Error of kurtosis to plus twice the Std.Error of kurtosis, we see that the kurtosis value falls within this range. Thus the non normal distribution is considered to be insignificant. The JSL variable was also tested for the the distrubution normality depending on “Branch” and “Work Exp” variables. (Appendix, Histogram). Descriptive statistics of the subsamples shows that the skewness and kurtosis is acceptable , no outliers were......

Words: 2253 - Pages: 10

Premium Essay

...Question catalogue: Statistics Self-Study Module Master's programme Media and Communication Science If you are master student of the master programme “Media and Communication Science” and have to fulfill the additional requirement: Self-Study Module Statistics, you have to answer these list of 42 questions. Please answer the following questions concerning statistical methods in social science briefly. Helpful information concerning the questions can be found in the Reader: “Statistics”. Enjoy yourself while answering the questions. Chapter 1 1. A client rates her satisfaction with her vocational counselor on a 4-point scale from 1 = not at all satisfied to 4 = very satisfied. What is the (a) variable, (b) possible values, and (c) score? 2. Give the level of measurement for each of the following variables: (a) ethnic group to which a person belongs, (b) number of times an animal makes a wrong turn in a maze, and (c) position one finishes in a race. 3. Fifty students were asked how many hours they had studied this weekend. Here are their answers: 11, 2, 0, 13, 5, 7, 1, 8, 12, 11, 7, 8, 9, 10, 7, 4, 6, 10, 4, 7, 8, 6, 7, 10, 7, 3, 11, 18, 2, 9, 7, 3, 8, 7, 3, 13, 9, 8, 7, 7, 10, 4, 15, 3, 5, 6, 9, 7, 10, 6 Make (a) a frequency table and (b) a frequency polygon. (c) Make a grouped frequency table using intervals of 0-5, 6-10, 11-15, 16-20. Based on the grouped frequency table, (d) make a histogram and (e) describe the general shape of the distribution. 4. Below are the number......

Words: 3576 - Pages: 15

Premium Essay

...Breakdown Grouping customers on the basis of marital status and gender as shown on Table 2, it seems that Pelican stores have more married customers than single customers. Of those married customers, the majority of them are female. It appears the relevant frequency for married females and everyone else is 80% and 20% respectively. Also it seems married customers spend more money on purchases at the store more than single customers, average spend by married and singles appears to be $78.03 and $75.35 respectively (Table 6 on page 5). Pie Chart of Genders with Marital Status 4% 3% Married Female 13% Married Male Single Female 80% Single Male +Pelican Stores Managerial Report 3 Data on Regular Customer Table 3 is a descriptive statistics for net sales by regular and promotion customers. It appears that customers taking advantage of the promotional coupons spent more on average. The mean amount spent by regular customers is $61.99 versus $ 84 by promotional customers. The relative frequency of regular and promotional customers is 30% and 70% respectively. Net Sales by Customer Type Regular Promotions Mean 61.99 Mean Median 51 Median Sample Variance 1229.76 Sample Variance Standard Deviation 35.07 Standard Deviation First Quartile 39.5 Minimum Third Quartile 74 Maximum Count 30 Count Table 3. 84 63.42 3777.61 61.46 13.23 287.59 70 The 80th percentile of Net Sales for Each Payment Method Table 4 represent date on sales for all card categories as used by......

Words: 753 - Pages: 4

Free Essay

...Statistical Information Paper I will describe the use of statistic at Veterans hospital in Loma Linda that has 142 Hospital beds and 108 beds of Community Living Center. Employs 2,436 staff. The VA hospital Provided 546,017 outpatients visits in 2008.In 2010 Outpatients visits 584,028 it is increase 38011 or increase 1.07%. Statistics is data use to compare and analysis. Hospital statistics Includes current and historical data on utilization revenue, expenses, person and mush morel Will describe numerical data, numerical count, statically analysis, and four levels of Measurement. Numerical data. Bennett, Briggs, and Troika (2009). Numerical Numerical data is identified, measured, and numerical scale. Numerical data can be Displayed using charts, tables, and graphs. Example I work at medical floor is a busy floor. The Physician is always order many test for the new admit patient. Such as Order the patient, take X-Ray, EKG, CAT scan, GI lab so on. For example, if the patients come back for GI lab.Nurse has To take vital sign every 15 minutes times four, every 30 minutes times two, and one-hour time One. This Vital sign was taken to compare how the vital sign are difference between them. If the vital Sign Drop too low or too high that will nurse alert nurse to check the patient and report to the Physician right away. This entire vital sign nurse has to record in the computer that will show in Line graph. The line graph is easy to...

Words: 813 - Pages: 4

Premium Essay

...Introductory STATISTICS 9TH EDITION This page intentionally left blank Introductory STATISTICS 9TH EDITION Neil A. Weiss, Ph.D. School of Mathematical and Statistical Sciences Arizona State University Biographies by Carol A. Weiss Addison-Wesley Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montreal Toronto Delhi Mexico City Sao Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo On the cover: Hummingbirds are known for their speed, agility, and beauty. They range in size from the smallest birds on earth to several quite large species—in length from 2 to 8.5 inches and in weight from 0.06 to 0.7 ounce. Hummingbirds ﬂap their wings from 12 to 90 times per second (depending on the species) and are the only birds able to ﬂy backwards. Normal ﬂight speed for hummingbirds is 25 to 30 mph, but they can dive at speeds of around 60 mph. Cover photograph: Hummingbird, Editor in Chief: Deirdre Lynch Acquisitions Editor: Marianne Stepanian Senior Content Editor: Joanne Dill Associate Content Editors: Leah Goldberg, Dana Jones Bettez Senior Managing Editor: Karen Wernholm Associate Managing Editor: Tamela Ambush Senior Production Project Manager: Sheila Spinney Senior Designer: Barbara T. Atkinson Digital Assets Manager: Marianne Groth Senior Media Producer: Christine Stavrou Software Development: Edward Chappell, Marty Wright C iDesign/Shutterstock Marketing Manager: Alex Gay Marketing......

Words: 377092 - Pages: 1509

Premium Essay

...1. Introduction Poverty, which is measured by the household income lower than poverty line has been identified as the dependent variable in this project. It is important to know which elements are associated with poverty. The purpose of this paper is to evaluate the key determinants of American household poverty in 1980. The four possible determinants will be analyzed in this project, the average numbers of every family (FAMSIZE), URB is the percent of people live in urban, UR is the level of people have no job over 16 years and the median family income in US dollars (INCOME). Descriptive statistics, correlation and regression will be used in this project. 2. Descriptive statistics Variable | Mean | Median | Mode | VAR | STDEV | URB | 58.76034483 | 66.15 | 0 | 1012.828049 | 31.82495953 | FAMSIZE | 3.140172414 | 3.135 | 2.93 | 0.033377163 | 0.182694178 | UR | 9.293103448 | 8.95 | 5.8 | 10.92696915 | 3.30559664 | INCOME | 19240.43103 | 18512 | N/A | 10889936.04 | 329.990309 | POV | 9.120689655 | 9.05 | 8.8 | 6.230792498 | 2.496155544 | 3. Correlation Correlation and regression are techniques for investigating the statistical relationship between two, or more, variables (Barrow, 2013, pp. 238). * Correlation defines the degree to which there is a linear relationship between pairs of variables. Firstly, it is useful to graph the variables to see if anything useful is revealed. In this case, XY graphs are the most suitable and they are shown in......

Words: 1666 - Pages: 7

Premium Essay

...The article I chose suggests that Roman Catholics in the United States hope that the next pope could be younger and lead the church in a more liberal way regarding issues, such as birth control and same-sex marriage. The statistics is based on the latest New York Times/CBS News telephone poll conducted on landlines and cellphones from February 23 to 27 with 1,585 adults nationwide. Three-fourths of interviewers thought Pope Benedict should step down because he did a bad job dealing with sexual abuse. The poll suggested that many American Catholics are not confident about the church’s hierarchy since the bishops and cardinals do not understand their needs. The sample of telephone poll was randomly selected to ensure that each region of the country has almost same share of all telephone numbers, so it seems justified geographically. However, there is uncertainty in the survey because the margin of sampling error is plus or minus 4% for the 580 Catholics. An effective way to reduce the margin of error is to increase the sample size. There is also nonresponse error in the survey because some people do not answer calls from strangers, or refuse to answer the poll. In addition, due to selection bias, the opinions of those who agreed to be interviewed only reflect a certain part of the population. The article did well in analyzing from a series of data, mainly on the percentage of sample size. For example, the poll showed that 40 percent thought the pope is......

Words: 332 - Pages: 2

Premium Essay

...variable Measurement units? EXAMPLE. Which variables are quantitative and which are categorical? Employee # Age (years) Annual Income (in Performance 1,000s of dollars) Rating (1-5 scale) 5543 48 50 – 100 4.5 2431 34 20 – 49 3.9 7281 31 0 – 19 3.4 Job Type Management Clerical Maintenance 2. SURVEYS AND SAMPLING Population: _______ individuals with a common characteristic that you want to generalize about Parameter: fact or characteristic about _____________ Sample: ________ of population Statistic: fact or characteristic about ______________ EXAMPLE. Mattel claims that less than 5% of all its Hot Wheels toys are defective. When testing 100 Hot Wheels toys from a production run of 7000 toys, 7% were found to be defective. What is the: a) Population? c) Parameter? Poor (Biased) Sampling Convenience sampling: Choosing respondents that are __________ to obtain Voluntary response: Respondents volunteer, so those with __________ opinions are more likely to respond b) Statistic? d) Sample? Sampling Designs 1. Simple Random Sampling (SRS): Every individual has an equal chance of being selected 2. Stratified Random Sampling: Divide population into ______________ subgroups and randomly select from each stratum 3. Cluster Random Sampling: Divide population into ______________ subgroups that are representative of population and select a few clusters 4. Systematic Sampling: with a random starting point, select at regular intervals COMM 291 Review Package prepared......

Words: 2677 - Pages: 11

Premium Essay

...explain the quality control process. Hypothesis : Hypothesis H0 : µ = 12 Ha : µ ≠ 12 Level of Significance = 0.01 Z test : Z test z = Z values : Z values Test statistic (z value) for all the samples P value : P value P values (2*(1-z score))for all the samples Rejection of null hypothesis : Rejection of null hypothesis Rejection rule for two tailed test using p-value approach Reject H0 if p-value ≤ α Standard Deviation : Standard Deviation Computed standard deviation for each of the samples Quality Associates utttsav Download Share Add to Flag Embed Views: 292 Category: Education License: All Rights Reserved Presentation Description No description available. Comments Presentation Transcript Quality Associates : Case 1 Quality Associates Introduction : Introduction It is a case of a consulting firm which consults its clients regarding statistical procedures that is used to control the production process. In this case, Quality Associates has taken example with random sample size 30 of 4 samples i.e. 120 out of 800 given observations to explain the quality control process. Hypothesis : Hypothesis H0 : µ = 12 Ha : µ ≠ 12 Level of Significance = 0.01 Z test : Z test z = Z values : Z values Test statistic (z value) for all the samples P value : P value P values (2*(1-z score))for all the samples Rejection of null hypothesis : Rejection of null hypothesis Rejection......

Words: 332 - Pages: 2

Premium Essay

...plays a role in certain areas where the recidivism rates are increasing. Lastly we will discuss several implications that could possibly reduce these rates. Introduction: A criminal career is a sequence of offenses during a period of an individual’s life. This repetitive criminal behavior is called recidivism, and indicates the proportion that becomes involved in criminal behavior, at what age criminal behaviors begins, how long the criminal career lasts and the number of offenses typically committed during the course of the career (Farrington, 1992) Also defined as an estimate of the percentage of released prisoner who commit another offense. There are three different measures of recidivism according to the Bureau of Justice Statistics. These are rearrests, reconviction, and reincarceration. Rearrests is described as any arrest that was reported to state identification bureau after release from a correctional bureau after release from a correctional institute. Reconviction can be referred to as a conviction on at least one charge after the release date. Reincarceration refers to any return to prison or any admission to a local jail with a new offense. The Problem: Recidivism is associated with increases in crime, homelessness, and family destabilization. In many cases, high recidivism results to failure to provide useful rehabilitation for offenders. Recidivism rates in urban centers tend to be higher than In rural areas. Also some factors we must......

Words: 648 - Pages: 3

Premium Essay

...Statistics Name Institution Question 1 of 20 | 5.0 Points | When comparing two population means with an unknown standard deviation you use a t test and you use N-2 degrees of freedom. A. True | B. False | | Reset Selection Question 2 of 20 | 5.0 Points | Pretend you want to determine whether the mean weekly sales of soup are the same when the soup is the featured item and when it is a normal item on the menu. When it is the featured item the sample mean is 66 and the population standard deviation is 3 with a sample size of 23. When it is a normal item the sample mean is 53 with a population standard deviation of 4 and a sample size of 7. Given this information we could use a t test for two independent means. A. True | B. False | | Reset Selection Question 3 of 20 | 5.0 Points | The alternative hypothesis can be proven if the alternative hypothesis is rejected. A. True | B. False | | Reset Selection Question 4 of 20 | 5.0 Points | You want to determine if your widgets from machine 1 are the same as machine 2. Machine 1 has a sample mean of 50 and a population standard deviation 5 and a sample size of 100. Machine 2 has a sample mean of 52 and a population standard deviation of 6 with a sample size of 36. With an alpha of .10 can we claim that there is a difference between the output of the two machines. Which of the following statements are true? A. We will reject the null hypothesis and prove there is a difference between...

Words: 1999 - Pages: 8

Premium Essay

...Statistics Homework 1. Section 3.1, Exercise #14, p. 125 Finding Probabilities consider a company that selects employees for random drug tests. The company uses a computer to select randomly employee numbers that range from 1 to 6296. Find the probability of selecting a number greater than 1000. P(E) = Number of outcomes in E / Total number of Outcomes in sample space Number of outcomes in E = 6296 – 100 = 5296 The probability = P(E) = 5296 / 6296 = 0.841 = 84.1% There is an 84.1 percent probability of selecting a number greater than 1000 2. Section 3.1, Exercise #20, p. 126 Using a Frequency Distribution to Find Probabilities in use the frequency distribution, which shows the number of American voters (in millions) according to age. 18 to 20 years old 4.8 21 to 24 years old 7.3 25 to 34 years old 20.4 35 to 44 years old 28.4 45 to 64 years old 43.7 Find the probability that a voter chosen at random is between 35 and 44 years old. Probability = 28.4 / (4.8 + 7.3 + 20.4 + 28.4 + 43.7 + 24.9) = 0.2193 = 21.93% 3. Section 3.2, Exercise #16, p. 136 A doctor gives a patient a 60% chance of surviving bypass surgery after a heart attack. If the patient survives the surgery, he has a 50% chance that the heart damage will heal. Find the probability that the patient survives and the heart damage heals. Let BS be......

Words: 450 - Pages: 2