Question

1. Your mechanic estimates that the total weight of a filled tire for your particular vehicle is less than 20 pounds. Suppose that the total tire weight for vehicles that have your particular sized tire is normally distributed with standard deviation (s) 1.25 pounds. A random sample of 55 tires (similar in size to yours) has a sample mean weight of 18.75 pounds.    Use the “4-Step Process As Applied to Tests of Significance” to test your mechanic’s claim at the 0.01 level1
2. 1.What is the practical question that requires a statistical test?
3. 2. Identify the parameter

4. 3. List all the given info from the data collected

5. 4. state the null and alternative hypotheses

6. 5.specify the level of significance

7. 6.determine the type of test (left-tailed,right-tailed,two-tailed)

8. 7.sketch the region(s) of "extremely unlikely" test stats.

Answer 1

1.What is the practical question that requires a statistical test?

e total weight of a filled tire for your particular vehicle is less than 20 pounds

2. Identify the parameter

parameter is true mean weight of a filled tyre denoted with mu

mu=20

3. List all the given info from the data collected

popualtion mean=mu=20 pounds

sample mean=xbar=18.75 pounds

sample size=n=55

popualtion standard deviation =sigma=1.25 pounds

4. state the null and alternative hypotheses

Ho:

Ha:

5.specify the level of significance

alpha=0.01

6.determine the type of test (left-tailed,right-tailed,two-tailed)

From words

Total weight of a filled tire for your particular vehicle is less than 20 pounds

left tail test

7.sketch the region(s) of "extremely unlikely" test stats.

z=xbar-mu/sigma/sqrt(n)

z=(18.75-20)/(1.25/sqrt(55))

z= -7.416198

p=0

Reject Ho

Accept Ha