Author:
Christine Farr

MAT 160 – Hypothesis Testing HomeworkName _______________________1.) Employees in an accounting firm claim that the mean salary of the firm’s accountants is less than that ofits competitor’s which is $45,000. (Assume that the standard deviation of the firm’s accountants isknown to be $5,200.) A random sample of 30 of the firm’s accountants has a mean salary of $43,500.Test the employees claim at the .01 level of significance.1.4.2.3.5.2.) The U.S. Department of Agriculture reports that the mean cost of raising a child from birth to age 2 in arural area is $8390. You believe this value is incorrect, so you select a random sample of 900 children(age 2) and find that the mean cost is $8275. Assume the standard deviation for the cost of raising achild from birth to age 2 is $1540. Test your claim at the .05 level of significance.1.4.2.3.5.3.) You receive a brochure from a large university. The brochure indicates that the mean class size for fulltime faculty is less than 32. You want to test this claim. You randomly select 18 classes taught by fulltime faculty and determine the class size of each. The results are listed below. Can you support theuniversity’s claim at the .01 level of significance? Assume class size is known to be normallydistributed.

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