Question

The conclusion for the problems is probably the most important part- be sure to include both a conclusion about your Ho and Ha (you will start by defining those . . . ) and another sentence to summarize the answer to original research question (the context provided in the problem statement- like the Cheerios box weights in my example from the notes. . . )

. Batteries are supposed to last for 13 hours with a standard deviation of 0.31 hours. The quality control engineer is testing a new operating system and finds that a sample of 43 devices using the new operating system exhausts the batteries in a mean of 12.89 hours. Test to determine if the average life of the batteries when using the new operating system is significantly less than the stated life of 13 hours using a = 0.05.

Answer 1

H0: = 13

Ha: < 13

Test statistics

z = - / / sqrt(n)

= 12.89 - 13 / 0.31 / sqrt(43)

= -2.33

This is test statistics value.

p-value = P( Z < z)

= P( Z < -2.33)

= 0.0099

Since p-value < 0.05 level, we have sufficient evidence to reject the null hypothesis.

We conclude at 0.05 level that we have sufficient evidence to support the claim.