The high temperature X (in degrees Fahrenheit) on January days in Columbus, Ohio varies according to the Normal distribution with mean 21 and standard deviation 10. the value of P(X<10)is?

1 answer

Z = (score - Mean)/ Standard deviation.

Z = (10 - 21)/10

Look up Z score in table in back of your stat book labeled something like "areas under normal distribution." Since you want it <10, you would be looking for the proportion in the smaller area.