Question

The age for race car drivers were selected at random.

The following ages were obtained: 32 32 33 33 41 29 38 32 33 23 27 45 52 29 and 25.

(Give three decimals for all number answers.)

1.  What is the average for this sample?

2.  What is the standard deviation for this sample?

Use a .05 significance level to test the claim that the mean age of all race drivers is greater than 30 years.

3.  What is the significance level?  

4.  What test do you use? (normal, t-test, or Chi-square)

5.  What is the sample size?

6.  What is the sample mean?

7.  What is the sample standard deviation?

8.  What is the standard error of the mean?

9.  What are the degrees of freedom?  

10.  What is the absolute of the t Test Statistic?

11.  What is the absolute critical value?

12.  What is the p-value?

13.  Do you "reject" the null or "fail to reject" the null?

14.  From your data at the .05 significance level, can you conclude that the race car drivers are older than 30? (yes or no)

15.  At the .01 level, can you conclude that the race car drivers are older than 30? (yes or no)

Answer 1

1. The average for this sample is = 33.6

2. The standard deviation for this sample = 7.67

3. The significance level = 0.05

4. One should use - t-test

14. There is sufficient evidence to conclude that the race car drivers are older than 30.

15. Since P-value > 0.01, so we fail to reject the null hypothesis at 1% level of significance and we can conclude that there is not sufficient evidence to conclude that the race car drivers are older than 30.