Originally Posted by
leroywash1
I need help with the following 2 excersises. using the 5 steps of hypothesis testing and I need to show all calculations,
Use the five-step procedure for hypothesis testing in the following exercises
12. The National Safety Council reported that 52 per cent of American turnpike drivers are men. A sample of 300 cars traveling outbound on the New Jersey Turnpike yesterday revealed that 170 were driven by men. At the .01 significance level, can we conclude that a larger proportion of men were driving on the New Jersey Turnpike than the national statistics indicate?
17. Ms. Lisa Morin is the budget director for Nexus Media, Inc. She would like to compare the daily travel expense for the sales staff and the audit staff. She collected the following sample information.
Audit ($) 131 135 146 165 136 142
Sales ($) 130 102 129 143 149 120 129
At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the p-value?
Five-Step Procedure for Hypothesis Testing
1. Establish the hull hypothesis (H0) and the alternate hypothesis (H1).
2. Select the level of significance.
3. Select an appropriate test statistic.
4. Formulate a decision rule based on steps 1, 2, and 3 above.
5. Make a decision regarding the null hypothesis based on the sample information. Interpret the results of the test.
Question 17 - You must perform calculations for the mean. The mean is the sum of the values divided by the number of values. Obtain the answers for the mean for both variables (Audit and Sales).
You could use descriptive statistical software or do this manually with the use of a calculator. In order to test the level of significance you would need to use software or a Stats website for assistance.
Performing the calculations:
Audit mean = 142.50 or 143 rounded
Sales mean = 128.86 or 129 rounded
Performing significance test for "p-value" yields: Using Mean vs. Hypothesized value
testing at Alpha .10
Audit p-value = .5000 which is greater than .10
Sales p-value = .5002 which is greater than .10
Thus, with this specific question--- at alpha .10 signficance we CAN NOT conclude that the Mean for the sales travel expenses is greater than the audit expenses.
Going further however, if the alpha level of significance were tested at .5 then we could conclude with 95% onfidence that the Audit sales were greater than that of Sales---since .5000 is equal to .5. Yet, the sales p-value of .5002 is greater than .5 thus we would chose Audit as the final answer at the .5 level of significance.
Descriptive statistics
Audit
count 6
mean 142.50
sample variance 149.90
sample standard deviation 12.24
minimum 131
maximum 165
range 34
Descriptive statistics
Sales
count 7
mean 128.86
sample variance 234.48
sample standard deviation 15.31
minimum 102
maximum 149
range 47
Hypothesis Test: Mean vs. Hypothesized Value
142.500 hypothesized value
142.500 mean Audit
12.243 std. dev.
4.998 std. error
6 n
5 df
0.00 t
.5000 p-value (one-tailed, upper)
Hypothesis Test: Mean vs. Hypothesized Value
128.860 hypothesized value
128.857 mean Sales
15.313 std. dev.
5.788 std. error
7 n
6 df
0.00 t
.5002 p-value (one-tailed, upper)