Statistic Exercises

MBA – MS

Term 1 –fall 2017

Exercises October 17, 2017

Exercise 9.46 (a-d)

… The restaurant would like to test the hypothesis that the average delivery time is less than 30 minutes.  The following data represent a random sample of delivery times:

23   24   23   36   30   40   34   24   28   29   15   27  

Using α=0.10, answer the following

1. State the null and the alternative hypothesis
2. Does the sample provide enough evidence to support Season’s delivery system?
3. Verify your results using PHStat2
4. Report the p-value from PHStat2 and interpret to meaning.

Descriptive Statistics

Null Hypothesis: μ0=>30

We assume that the delivery waiting time is at least 30 minutes or equal to 30 minutes.

Alternative Hypothesis: μα<30 min

We assume that the delivery time is less than 30 minutes.

We use t-student to test the hypothesis

As p-value is 0.1361 and α=0.1 we do not reject the null hypothesis. That means the sample does not provide enough evidence that Season’s restaurant delivery system have a waiting time less than 30 minutes.

Probably clients are right and they have to wait more than Seasons claimed for delivery provide.

Exercise 9.47

Descriptive statistics

Null Hypothesis: μ0<=59.3 (Assuming resident doctors of the particular hospital are working less than 59.3 hours or exactly 59.3 hours per week)