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Finding a Random Sample (Example 5) You need to select a simple random sample of four from eight friends who will participate in a survey. Assume the friends are numbered 1, 2, 3, 4, 5, 6, 7, and 8.
Select four friends, using the two lines of numbers in the next column from a random number table.
Read off each digit, skipping any digit not assigned to one of the friends. The sampling is without replacement, meaning that you cannot select the same person twice. Write down the numbers chosen. The first person is number 7.
Which four friends are chosen?
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Chapter 7 Solutions
INTRODUCTORY STATISTICS (LOOSELEAF)
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- 2. An experiment is set up to test the effectiveness of a new drug for balancing people's mood. The table below contains the results of the patients before and after taking the drug. The possible scores are the integers from 0 to 10, where 0 indicates a depressed mood and 10 indicates and elated mood. Patient Before After 1 4 4 2 3 3 3 6 4 4 1 2 5 6 5 6 1 3 7 4 7 8 6 9 1 4 10 5 4 Assuming the differences of the observations to be symmetric, but not normally distributed, investigate the effectiveness of the drug at the 5% significance level. [4 Marks]arrow_forward3. (i) Consider the following R code: wilcox.test(UK Supermarkets $Salary ~ UKSupermarkets $Supermarket) (a) Which test is being used in this code? (b) What is the name of the dataset under consideration? How would be adapt this code if we had ties? What other command can be used which deals with ties? (ii) Consider the following R code: install packages("nortest") library(nortest) lillie.test (Differences) (a) Assuming the appropriate dataset has been imported and attached, what is wrong with this code? (b) If this code were to be corrected, what would be determined by run- ning it? [3 Marks]arrow_forward1. (i) Explain the difference in application between the Mann-Whitney U test and the Wilcoxon Signed-Rank test, i.e. in which scenarios would each test be used? (ii) What is the main procedure underlying these nonparametric tests? [3 Marks]arrow_forward
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