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## Homework Statement

Having problems solving some questions for Statistics class

The amount of time spent by North American adults watching TV per day is normally distributed with a mean of 6 hrs and a standard deviation of 1.5hrs.

a. What is the probability that a randomly selected North American adult watches TV for more than 7 hrs per day?

b. What is the probability that the average time watching TV by a random sample of 5 american adults is more than 7 hrs?

c. What is the probability that, in a random sample of 5 american adults, all watch TV for more than 7 hrs per day?

## Homework Equations

P(X>7)

## The Attempt at a Solution

Tried this but not sure if its correct

a. P(X>7)= (7-6/1.5)= .6667

=P(Z>.6667)= .2486

=0.5+.2486= .7486

The probablity that a randomly selected North American adult watches TV for more than 7 hrs per day is .7486%

Am i on the right path?

As for b and c I have no idea where to start.

Some advice/help would be much appreciated