Thread: Find the mean and standard deviation of the sum or difference of independent random v

what should i do for A?? and for B, is it asking me to convert all the temperatures to Fahrenheit?

They are asking for , and . You should have some formulas that should make the preceding quite simple.

yes i figured out how to get the mean... i just simply take the temperatures that are off target and minus it to 550... i got that part but what i don't know how to get is the standard deviation.... would you happen to know how to calculate that based on my problem??