An electronics manufacturing process has historically had a mean completion time of 70minutes. It is claimed that, due to improvements in the process, the mean completion time, μ, is now less than 70 minutes. A random sample of 10 completion times using the new process is taken. The sample has a mean completion time of 62 minutes, with a standard deviation of 11 minutes. Assume that completion times using the new process are approximately normally distributed. At the 0.05 level of significance, can it be concluded that the population mean completion time using the new process is less than 70 minutes? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. A. Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an example problem and the equation to use, with the correct answer as every expert I have asked thus far has gotten this problem wrong.) B. Find the critical value. (Round to three or more decimal places.) C. Can it be concluded that the mean completion time using the new process is less than 70 minutes?
An electronics manufacturing process has historically had a mean completion time of 70minutes. It is claimed that, due to improvements in the process, the mean completion time, μ, is now less than 70 minutes. A random sample of 10 completion times using the new process is taken. The sample has a mean completion time of 62 minutes, with a standard deviation of 11 minutes. Assume that completion times using the new process are approximately
A. Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an example problem and the equation to use, with the correct answer as every expert I have asked thus far has gotten this problem wrong.)
B. Find the critical value. (Round to three or more decimal places.)
C. Can it be concluded that the mean completion time using the new process is less than 70 minutes?
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