The operational endurance of a random sample of 15 'Volt-X' industrial sensors is measured under standard load. The mean endurance of the sample is recorded as $hours118.4\text{ hours}$ . The endurance times of these sensors are known to follow a normal distribution.

Given that the population standard deviation for these sensors is $hours4.2\text{ hours}$ ,

estimate the limits between which $95%95\%$ of the endurance times of individual sensors lie.

find a $98%98\%$ confidence interval for the mean endurance time of the 'Volt-X' sensors.

A quality control engineer claims that the true mean endurance time of these sensors is $hours121.5\text{ hours}$ .

Comment on the engineer's claim. Give a reason for your answer.

Given that the population standard deviation for these sensors is $hours4.2\text{ hours}$ ,

estimate the limits between which $95%95\%$ of the endurance times of individual sensors lie.

find a $98%98\%$ confidence interval for the mean endurance time of the 'Volt-X' sensors.

A quality control engineer claims that the true mean endurance time of these sensors is $hours121.5\text{ hours}$ .

Comment on the engineer's claim. Give a reason for your answer.

2.5.8 Hypothesis test for a single mean (A-level only)

Question 36

Markscheme

2.5.8 Hypothesis test for a single mean (A-level only)

Question 36

Markscheme

2.5.8 Hypothesis test for a single mean (A-level only)

Question 36

2.5.8 Hypothesis test for a single mean (A-level only) Questions

2.5.8 Hypothesis test for a single mean (A-level only)

Question 36

2.5.8 Hypothesis test for a single mean (A-level only) Questions