Posted: February 8th, 2019

Suppose a study reports that the average price for a gallon of self-serve

Question
2

Suppose a study reports that the average price
for a gallon of self-serve regular unleaded gasoline is $3.16. You believe that
the figure is higher in your area of the country. You decide to test this claim
for your part of the United States by randomly calling gasoline stations. Your
random survey of 25 stations produces the following prices (all in $). Assume
gasoline prices for a region are normally distributed. Did the data you
obtained provide enough evidence to reject the claim? Use a 1% level of
significance. Make sure you clearly state both the null and the alternative
hypotheses in full sentences. Following your calculations, clearly state the
conclusion in the same manner (do not simply say “accept/reject “null”) and
explain how you arrived at this conclusion (based on which metrics).
Question 4

To answer this question, use the Data Analysis Toolpack in
Excel and select “t-Test: Two-Sample Assuming Equal Variances” from the list of
available tools. Conduct a hypothesis test using this tool. Explain your answer
(how you decided if men spend more or not) and include the output table. Some
studies have shown that in the United States, men spend more than women buying
gifts and cards on Valentine’s Day. Suppose a researcher wants to test this
hypothesis by randomly sampling 9 men and 10 women with comparable demographic
characteristics from various large cities across the United States to be in a
study. Each study participant is asked to keep a log beginning 1 month before
Valentine’s Day and record all purchases made for Valentine’s Day during that
1-month period. The resulting data are shown below. Use these data and a 1%
level of significance to test to determine if, on average, men actually do
spend significantly more than women on Valentine’s Day. Assume that such
spending is normally distributed in the population and that the population
variances are equal. Make sure you clearly state both the null and the
alternative hypotheses in full sentences. Include the output table; then
clearly state the conclusion in the same manner (do not simply say
“accept/reject null”), and explain how you arrived at this conclusion (based on
which metrics).

Men Women
107.48 125.98
143.61 45.53
90.19 96.35
125.53 80.62
70.79 46.37
83 84.34
129.63 75.21
154.22 68.48
93.8 65.84
126.11