Use the following information to answer the next three exercises: Richard’s Furniture Company delivers furniture from 10 A.M. to 2 P.M….

Use the following information to answer the next three exercises: Richard’s Furniture Company delivers furniture from

10 A.M. to 2 P.M. continuously and uniformly. We are interested in how long (in hours) past the 10 A.M. start time that

individuals wait for their delivery.

 Χ ~ _____(_____,_____)

a. U(0,4)

b. U(10,2)

c. Eχp(2)

88. Facebook provides a variety of statistics on its Web site that detail the growth and popularity of the site.

On average, 28 percent of 18 to 34 year olds check their Facebook profiles before getting out of bed in the morning. Suppose

this percentage follows a normal distribution with a standard deviation of five percent.

a. Find the probability that the percent of 18 to 34-year-olds who check Facebook before getting out of bed in the

morning is at least 30.

b. Find the 95th percentile, and express it in a sentence.

66. Height and weight are two measurements used to track a child’s development. TheWorld Health Organization measures

child development by comparing the weights of children who are the same height and the same gender. In 2009, weights for

all 80 cm girls in the reference population had a mean μ = 10.2 kg and standard deviation σ = 0.8 kg. Weights are normally

distributed. X ~ N(10.2, 0.8). Calculate the z-scores that correspond to the following weights and interpret them.

a. 11 kg

b. 7.9 kg

c. 12.2 kg