The 95% confidence interval for these parts is 56.98 to 57.05 under normal operations. A systematic sample is taken from the manufacturing line to determine if the production process is still within acceptable levels. The mean of the sample is 56.99. What should be done about the production line?

Stop the line as it is outside the confidence interval

Keep the line operating as it is inside the confidence interval

Stop the line as it is inside the confidence interval

Keep the line operating as it is outside the confidence interval

Keep the line operating as it is inside the confidence interval

Step-by-step explanation:

A confidence interval of a proportion p% at the x% level with m% margin of error means that:

We are x% sure that the true mean of the population is in the interval from (p-x) % to (p+x) %.

In this problem, we have that:

The 95% confidence interval for these parts is 56.98 to 57.05 under normal operations. This means that we are 95% that these parts are between 56.98 and 57.05.

The mean of the sample is 56.99. This is inside the confidence interval.

The correct answer is:

Keep the line operating as it is inside the confidence interval