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1. The following data are the times in seconds that it took a sample of employee

ID: 3159600 • Letter: 1

Question

1. The following data are the times in seconds that it took a sample of employees to assemble a component at Ental Industries manufacturing facility: 190; 198; 180; 181; 208; 198; 199; 176; 174; 183; 188; 165. Assembly times are normally distributed. At the .10 significance level, can we conclude that the mean assembly time for this component is not equal to 3 minutes? What rejection region should be used?

a. Reject H0 if the test statistics > 1.796 or < -1.796

b. Reject H0 if the test statistic > 1.96 or < -1.96

c. Reject H0 if the test statistic > 1.363 or < -1.363

2.

The following data are the times in seconds that it took a sample of employees to assemble a component at Ental Industries manufacturing facility: 190; 198; 180; 181; 208; 198; 199; 176; 174; 183; 188; 165. Assembly times are normally distributed. At the .10 significance level, can we conclude that the mean assembly time for this component is not equal to 3 minutes? What decision should be made?

Average assembly time is about 3 minutes

Average assembly time is not equal to 3 minutes

Reject H0 and Ha at the same time

a.

Average assembly time is about 3 minutes

b.

Average assembly time is not equal to 3 minutes

c.

Reject H0 and Ha at the same time

Explanation / Answer

1) For two-tailed test, rejection region a) [t11,0.10=1.796]

2) t=(xbar-mu)/(s/sqrt n)

=(186.67-180)/(12.47/sqrt 12)

=1.85

The test statistic falls in critical region. Reject H0. Conclude b)