Although studies continue to show smoking leads to significant health problems, 20% of adults in the United States smoke. Consider a group of 350 adults. If required, round your answers to four decimal places.

a. What is the expected number of adults who smoke?
b. What is the probability that fewer than 20 smoke?
c. What is the probability that from 45 to 80 smoke?
d. What is the probability that 70 or more smoke?

a. The expected number of adults who smoke is 70

b. The probability that fewer than 20 smoke is 5.7%

c. The probability that from 45 to 80 smoke is the 12,8% to 22,8%

d. The probability that 70 or more smoke is the 20%

Explanation:

a. 350 is the 100% so you have to do a equation

350 -100%

 X   - 20% =   20% x 350/100  = 70 adults

b. 350 -100%

    20   - X = 20% x 100%/350= 5.7% probability

c. 350 - 100%

   45   -   X = 45 x 100%/350= 12.8% probability

   350 - 100%

    80  -  X = 80 x 100%/350= 22.8% probability

d. 350 -  100%

    70   -  X = 70 x 100%/350= 20%  probability