
Concept explainers
The annual incomes of a sample of middle-management employees at Westinghouse are $62,900, $69,100, $58,300, and $76,800.
- (a) Give the formula for the sample
mean . - (b) Find the sample mean.
- (c) Is the mean you computed in (b) a statistic or a parameter? Why?
- (d) What is your best estimate of the population mean?
(a)

Mention the formula for the sample mean.
Answer to Problem 1.1SR
The formula for sample mean is
Explanation of Solution
Sample mean:
The sample mean is the sum of all data values in the sample, divided by total number of data values from the sample. The formula for sample mean is,
In notations the formula for sample mean is,
In the formula,
(b)

Find the sample mean for a sample of annual incomes of middle-management employees at Westinghouse.
Answer to Problem 1.1SR
The sample mean for a sample of annual incomes of middle-management employees at Westinghouse is $66,775.
Explanation of Solution
Calculation:
The number of data values in the sample is 4.
Add all values of sample for ‘
Hence, the sample mean for a sample of annual incomes of middle-management employees at Westinghouse is $66,775.
(c)

Identify whether the mean is a statistic or parameter.
Answer to Problem 1.1SR
The mean calculated is a statistic as it is calculated for the sample values.
Explanation of Solution
Parameter:
The characteristic that is measurable for a population in the study is denoted as parameter.
Statistic:
The characteristic that is measurable for a sample in the study is denoted as statistic.
The mean is calculated for a sample of annual incomes middle-management employees at Westinghouse. Since mean is calculated for the sample data values it would represent the measurable characteristic for the sample. This shows that, the mean calculated is a statistic.
Hence, the mean calculated is a statistic as it is calculated for the sample values.
(d)

Find the best estimate of the population mean.
Answer to Problem 1.1SR
The best estimate of the population mean is sample mean value $66,775.
Explanation of Solution
The best estimate for any population is its sample. Thus, the best estimate for the population mean would be its sample mean.
The sample mean for annual incomes of middle-management employees at Westinghouse is $66,775. The value $66,775 would be the best estimate for population mean.
Hence, the best estimate of the population mean is sample mean value $66,775.
Want to see more full solutions like this?
Chapter 3 Solutions
Loose Leaf for Statistical Techniques in Business and Economics
- Q.3.2 A sample of consumers was asked to name their favourite fruit. The results regarding the popularity of the different fruits are given in the following table. Type of Fruit Number of Consumers Banana 25 Apple 20 Orange 5 TOTAL 50 Draw a bar chart to graphically illustrate the results given in the table.arrow_forwardQ.2.3 The probability that a randomly selected employee of Company Z is female is 0.75. The probability that an employee of the same company works in the Production department, given that the employee is female, is 0.25. What is the probability that a randomly selected employee of the company will be female and will work in the Production department? Q.2.4 There are twelve (12) teams participating in a pub quiz. What is the probability of correctly predicting the top three teams at the end of the competition, in the correct order? Give your final answer as a fraction in its simplest form.arrow_forwardQ.2.1 A bag contains 13 red and 9 green marbles. You are asked to select two (2) marbles from the bag. The first marble selected will not be placed back into the bag. Q.2.1.1 Construct a probability tree to indicate the various possible outcomes and their probabilities (as fractions). Q.2.1.2 What is the probability that the two selected marbles will be the same colour? Q.2.2 The following contingency table gives the results of a sample survey of South African male and female respondents with regard to their preferred brand of sports watch: PREFERRED BRAND OF SPORTS WATCH Samsung Apple Garmin TOTAL No. of Females 30 100 40 170 No. of Males 75 125 80 280 TOTAL 105 225 120 450 Q.2.2.1 What is the probability of randomly selecting a respondent from the sample who prefers Garmin? Q.2.2.2 What is the probability of randomly selecting a respondent from the sample who is not female? Q.2.2.3 What is the probability of randomly…arrow_forward
- Test the claim that a student's pulse rate is different when taking a quiz than attending a regular class. The mean pulse rate difference is 2.7 with 10 students. Use a significance level of 0.005. Pulse rate difference(Quiz - Lecture) 2 -1 5 -8 1 20 15 -4 9 -12arrow_forwardThe following ordered data list shows the data speeds for cell phones used by a telephone company at an airport: A. Calculate the Measures of Central Tendency from the ungrouped data list. B. Group the data in an appropriate frequency table. C. Calculate the Measures of Central Tendency using the table in point B. D. Are there differences in the measurements obtained in A and C? Why (give at least one justified reason)? I leave the answers to A and B to resolve the remaining two. 0.8 1.4 1.8 1.9 3.2 3.6 4.5 4.5 4.6 6.2 6.5 7.7 7.9 9.9 10.2 10.3 10.9 11.1 11.1 11.6 11.8 12.0 13.1 13.5 13.7 14.1 14.2 14.7 15.0 15.1 15.5 15.8 16.0 17.5 18.2 20.2 21.1 21.5 22.2 22.4 23.1 24.5 25.7 28.5 34.6 38.5 43.0 55.6 71.3 77.8 A. Measures of Central Tendency We are to calculate: Mean, Median, Mode The data (already ordered) is: 0.8, 1.4, 1.8, 1.9, 3.2, 3.6, 4.5, 4.5, 4.6, 6.2, 6.5, 7.7, 7.9, 9.9, 10.2, 10.3, 10.9, 11.1, 11.1, 11.6, 11.8, 12.0, 13.1, 13.5, 13.7, 14.1, 14.2, 14.7, 15.0, 15.1, 15.5,…arrow_forwardPEER REPLY 1: Choose a classmate's Main Post. 1. Indicate a range of values for the independent variable (x) that is reasonable based on the data provided. 2. Explain what the predicted range of dependent values should be based on the range of independent values.arrow_forward
- In a company with 80 employees, 60 earn $10.00 per hour and 20 earn $13.00 per hour. Is this average hourly wage considered representative?arrow_forwardThe following is a list of questions answered correctly on an exam. Calculate the Measures of Central Tendency from the ungrouped data list. NUMBER OF QUESTIONS ANSWERED CORRECTLY ON AN APTITUDE EXAM 112 72 69 97 107 73 92 76 86 73 126 128 118 127 124 82 104 132 134 83 92 108 96 100 92 115 76 91 102 81 95 141 81 80 106 84 119 113 98 75 68 98 115 106 95 100 85 94 106 119arrow_forwardThe following ordered data list shows the data speeds for cell phones used by a telephone company at an airport: A. Calculate the Measures of Central Tendency using the table in point B. B. Are there differences in the measurements obtained in A and C? Why (give at least one justified reason)? 0.8 1.4 1.8 1.9 3.2 3.6 4.5 4.5 4.6 6.2 6.5 7.7 7.9 9.9 10.2 10.3 10.9 11.1 11.1 11.6 11.8 12.0 13.1 13.5 13.7 14.1 14.2 14.7 15.0 15.1 15.5 15.8 16.0 17.5 18.2 20.2 21.1 21.5 22.2 22.4 23.1 24.5 25.7 28.5 34.6 38.5 43.0 55.6 71.3 77.8arrow_forward
- In a company with 80 employees, 60 earn $10.00 per hour and 20 earn $13.00 per hour. a) Determine the average hourly wage. b) In part a), is the same answer obtained if the 60 employees have an average wage of $10.00 per hour? Prove your answer.arrow_forwardThe following ordered data list shows the data speeds for cell phones used by a telephone company at an airport: A. Calculate the Measures of Central Tendency from the ungrouped data list. B. Group the data in an appropriate frequency table. 0.8 1.4 1.8 1.9 3.2 3.6 4.5 4.5 4.6 6.2 6.5 7.7 7.9 9.9 10.2 10.3 10.9 11.1 11.1 11.6 11.8 12.0 13.1 13.5 13.7 14.1 14.2 14.7 15.0 15.1 15.5 15.8 16.0 17.5 18.2 20.2 21.1 21.5 22.2 22.4 23.1 24.5 25.7 28.5 34.6 38.5 43.0 55.6 71.3 77.8arrow_forwardBusinessarrow_forward
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillCollege AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALFunctions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage LearningAlgebra: Structure And Method, Book 1AlgebraISBN:9780395977224Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. ColePublisher:McDougal Littell





