Answer to Question #139878 in Statistics and Probability for Eshima

Question

What is the probability that Mike spends at most 240 min on online gaming if his mean time spent on it is 270 min with a standard deviation time of 15 min?

Answer 1

Let's assume that time spent is normally distributed.

$P(x<240)=P(z<\frac{240-270}{15})$

$=P(z<-2)=0.0228$