Question

tisti 16 of 17 (14 complete) see score on Help You want to buy a mean repair cost of 26 Model A machine, and a sa is $205. Assume the population standard deviation is $15. The mean repair cost of 20 Model B washing machines is see score n standard is $23. At a-0.01, can you reject the salesperson's claim? Assume the samples are random and independent, and parts (a) through (e). past due (a) Identify the claim and state Ho and Ha O A. The mean repair costs for Model A and Model B are different O B. The mean repair cost for Model A is greater than Model B O C. The mean repair costs for Model A and Model B are equal O D. The mean repair cost for Model A is less than Model B past due past due Lein be the mean repair cost for Model A and let μ2 be the mean repair cost for Model B What are Ho and Ha? past due past due past due 10:5 01/19/19 re to search

Answer 1

a) Option - C) The mean repair costs for Model A and Model B are equal.

Option - A) H₀: $\dpi{100} \mu1 = \mu2$

                  H₁: $\dpi{100} \mu1 \neq \mu2$

b) At alpha = 0.01, the critical values are z_0.005 = +/- 2.58

Reject H₀, if z < -2.58 or z > 2.58

Option - A) z < -2.58, z > 2.58

c) The test statistic z = ($\dpi{100} \bar x1 - \bar x2$)/$\dpi{100} \sqrt{\sigma1^2/n1 &plus; \sigma2^2/n2}$

                                  = (205 - 224)/sqrt((15)^2/26 + (23)^2/20)

                                  = -3.21

d) Since the test statistic value is less than the lower critical value (-3.21 < -2.48), so we should reject H₀.

Option - C) Reject H₀. The standardized test statistic is in a rejection region.

e) At the 1% significance level, there is insufficient evidence to support the claim that the mean repair costs for model A are equal to the mean repair costs for model B.