probability and statistics

QUIZ 1

Exercise 1

In the attached employee data, 

1. Graph the bar chart for sex, pie chart for sex and histogram for age.

2. Compute the mean and median for age. 

Exercise 2

1. A manufacturer of inkjet printers claim that only 5% of their printers require repairs within the first year. If of a random sample of 18 of the printers, four required repairs within the first year, does this tend to refute or support the manufacturer’s claim?

2. The scores of an examination are assumed to be normally distributed with μ = 75 and σ2 = 64. What is the probability that a score chosen at random will be greater than 85?