Smartphones: A Pew Research report indica ted that 37% of teenagers aged 12- 17 own smartphones. .A random sample of 150 teenagers is drawn.

1. Find the mean ft . 4
2. Find the standard deviation aft.
3. Find the probability that more than 35% of the sampled teenagers own a smartphone.
4. Find the probability that the proportion of the sampled teenagers who own a smartpbone is between 0.38 and 0.45.
5. Find the probability that less than 40% of the sampled teenagers own smartphones.
6. Would it be unusual if less than 31% of the sampled teenager s owned smartphones?