The length of an instant message conversation is normally distributed with a mean of 5 minutes and a standard deviation of .7 minutes. What is the probability that a conversation lasts longer than 6 minutes?

Question

anonymous · Answer

6 minutes is $\frac{6-5}{.7}=\frac{1}{.7}$ as a "z" score
you have to look up in a table to see what percent is above that z score

anonymous · Answer

$\frac{1}{.7}=1.4289$ rounded. do you have a table to look this up in?

anonymous · Answer

yes I do, thank you!

anonymous · Answer

once you look it up, subtract from 1, because this is the percent that is BELOW that z score, not above it

anonymous · Answer

who needs a table? use this http://homepage.stat.uiowa.edu/~mbognar/applets/normal.html

anonymous · Answer

plug in $\mu =5, x=6, \sigma = .7$ and choose $P(X>x)$ from the drop down

iluvsoccer · Answer

@anonymous already did it... :/

iluvsoccer · Answer

@Elsa213