I know this will be a basic question for most of you but I a

I know this will be a basic question for most of you but I am stuck on what is probably a very simple equation.My homework question is:

I am stuck on d. I, for some reason, cannot find the equation for figuring out X bar. I have looked through the various answer boards and see that answers such as the z score is -0.3853 and the X is 99.2294, but where are the respondents finding -0.3853 on the z table? I am not finding this, nor can i find within my text the way to figure out how to get to the -0.3853. Can anyone help walk me through this?

7.15 Given a normal distribution with = 100 and = 10, ifyou select a sample of n = 25, what is the prob- ability that A is a. less than 95? b. between 95 and 97.5? c. above 102.2? d. There is a 65% chance that X is above what value?

Solution