The average life expectancy of dishwashers produced by a company ...

[colton]

The average life expectancy of dishwashers produced by a company is 6 years with a standard deviation of 8 months. Assume that the lives of dishwashers are normally distributed.
 a. What is the probability that a randomly selected dishwasher will have a life expectancy of at least 7 years?
  b. Dishwashers that fail operating in less than 4.5 years will be replaced free of charge. What percent of dishwashers are expected to be replaced free of charge?
  c. What are the minimum and the maximum life expectancy of the middle 95 of the dishwashers' lives? Give your answer in months.
  d. If 155 of this year's dishwasher production fail operating in less than 4 years and 4 months, how many dishwashers were produced this year?

Question 2

Twenty percent of the employees of a large company are female. Use the normal approximation of the binomial probabilities to answer the following questions. What is the probability that in a random sample of 80 employees
 a. exactly 16 will be female?
  b. 14 or more will be female?
  c. 15 or fewer will be female?
  d. 18 or more will be female
  e. exactly 17 will be female?

[courtney_bruh]

Answer to Question 1

a. 0.0668
b. 1.22
c. 56.32 and 87.68 (Months)
d. 25,000

Answer to Question 2

a. 0.1114
b. 0.7580
c. 0.4443
d. 0.3372
e. 0.1071

[colton]

TYSM

[triiciiaa]

Gracias!