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9. (8 pts) A large software company gives job applicants a test of programming a

ID: 3323817 • Letter: 9

Question

9. (8 pts) A large software company gives job applicants a test of programming ability and the mean for that test has been 160 in the past. Twenty-five job applicants are randomly selected from one large university and they produce a mean score and standard deviation of 183 and 12, respectively. Use a 0.05 level of significance to test the claim that the mean score is greater than 160. Assume that the sample has been randomly selected from a population with a normal distribution 10. (8pts) California Department of Motor Vehicle (DMV) records indicate that of all ehicles undergoing emissions testing during 2016, 70% passed on the first try. late in 017 the state implemented a program designed to encourage preventative service to aprove emissions compliance. Of 126 randomly selected reports on emissions, 95 cars s on the first try. Does this program work? Test at the 5% level.

Explanation / Answer

#9.
Below are the null and alternate hypothesis.
H0: mu = 160
H1: mu > 160

Test statistics, t = (183 - 160)/(12/sqrt(25)) = 9.5833

p-value = 0.0000

As p-value is less than the significance level of 0.05, we reject the null hypothesis

This means there are significant evidence to conclude that test score is greater than 160