Question

The length of a text messaging conversation is normally distributed with a mean of 2 minutes and a standard deviation of 0.5 minutes. What is the probability that a conversation lasts longer than 3 minutes? 

Answer 1

On virtual school, the answer is 0.02275

Answer 2

Okay.consider  A as  the length of a text message conversation.
p(a>3)=1-p(b<3-2)/0.5)=1-0.97725= 0.02275.
 hope i help.
good luck!