Share
Explore BrainMass

Hypothesis Testing and Manufacturing Process Time

7) An electronics manufacturing process has a scheduled mean completion time of 75 minutes. It is claimed that, under new management, the mean completion time is less than 75 minutes. To test this claim, a random sample of 9 completion times under new management was taken.
The sample had a mean completion time of 73 minutes and a standard deviation of 8 minutes. Assume that the population of completion times under new management is normally distributed. At the 0.05 level of significance, can it be concluded that the mean completion time under new management is less than the scheduled mean?

Perform a one-tailed test...Carry your intermediate computations to at least three decimal places and round your answers.
The null hypothesis
The alternate hypothesis
The type of test statistic
The value of the test statistic (round three decimal places)
The p-value (round three decimal places)
At the 0.05 level, can it be concluded that the mean completion time under new management is less than the scheduled mean? (Yes or no)

8) A college professor claims that the entering class this year appears to be smarter than entering classes from previous years. He tests a random sample of 9 of this year's entering students and finds that their mean IQ score is 122, with standard deviation of 11. The college records indicate that the mean IQ score for entering students from previous years is 115. If we assume that the IQ scores of this year's entering class are normally distributed, is there enough evidence to conclude, at the 0.1 level of significance, that the mean IQ score of this year's class is greater than that of previous years?

Perform a one-tailed test...Carry your intermediate computations to at least three decimal places and round your answers.

The null hypothesis
The alternate hypothesis
The type of test statistic
The value of the test statistic (round three decimal places)
The critical value at the 0.1 level of significance.
Can we conclude, using the 0.1 level of significance that the mean IQ score of the year's class is greater than the previous year? (Yes or No)

Solution Preview

Please see the attached file.

7) An electronics manufacturing process has a scheduled mean completion time of 75 minutes. It is claimed that, under new management, the mean completion time is less than 75 minutes. To test this claim, a random sample of 9 completion times under new management was taken.
The sample had a mean completion time of 73 minutes and a standard deviation of 8 minutes. Assume that the population of completion times under new management is normally distributed. At the 0.05 level of significance, can it be concluded that the mean completion ...

Solution Summary

Hypothesis testing for intermediate computations are examined.

$2.19