For probability questions in this chapter concerning the sample mean, you MUST be given the population standard deviation (or at least the population variance which determine the standard deviation) and also the population mean. It will only be in later chapters that you will learn how to handle situations where they are both missing or either one is missing.

The number of pages produced by a fax machine in a busy office is normally distributed with a mean of 275 and a standard deviation of 75. Determine the probability that in 1 week (5 days) more than 1,500 faxes will be received.

Please help.. in such questions is it always this way that P(xbar > 15000/5)?
There were many questions like this in the textbook

Instead of asking you for the probability associated with the mean, they ask for the probability associated with the total. You first need to convert the total (Σx) into a sample mean by dividing it by n.

For question 1, you are given the mean and standard deviation, are there any cases where either or aren’t provided in the questinon

Thanks!

For probability questions in this chapter concerning the sample mean, you MUST be given the population standard deviation (or at least the population variance which determine the standard deviation) and also the population mean. It will only be in later chapters that you will learn how to handle situations where they are both missing or either one is missing.

The number of pages produced by a fax machine in a busy office is normally distributed with a mean of 275 and a standard deviation of 75. Determine the probability that in 1 week (5 days) more than 1,500 faxes will be received.

Please help.. in such questions is it always this way that P(xbar > 15000/5)?

There were many questions like this in the textbook

Yes – This is a very typical style of question.

Instead of asking you for the probability associated with the mean, they ask for the probability associated with the total. You first need to convert the total (Σx) into a sample mean by dividing it by n.

OK thank you