Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 80

Provide the following information
(a) What is the level of significance State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test
(b) Check Requirements What sampling distribution will you use Explain the rationale for your choice of sampling distribution. Compute the value of the sample test statistic.
(c) Find (or estimate) the P -value. Sketch the sampling distribution and show the area corresponding to the P -value.
(d) Based on your answer in parts (a) to (c), will you reject or fail to reject the null hypothesis Are the data statistically significant at level
(e) Interpret you conclusion in the context of the application.
Insurance: Hail Damage Nationally, about 11% of the total U.S. wheat crop is destroyed each year by hail (Reference: Agricultural Statistics , U.S. Department of Agriculture). An insurance company is studying wheat hail damage claims in Weld County, Colorado. A random sample of 16 claims in Weld County gave the following data (% wheat crop lost to hail).
15 8 9 11 12 20 14 11
7 10 24 20 13 9 12 5
The sample mean is
= 12.5%. Let x be a random variable that represents the percentage of wheat crop in Weld County lost to hail. Assume that x has a normal distribution and = 5.0%. Do these data indicate that the percentage of wheat crop lost to hail in Weld County is different (either way) from the national mean of 11% Use = 0.01.