All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.
Unbiased estimate of mean
Unbiased estimate of variance
Under , .
From graphing calculator, p-value , we do not reject .
Thus, there is insufficient evidence at 2.5% level of significance that this type of device can retain information for more than 75 hours.
KS Comments
This question is fairly manageable.
[…] Question 7 […]