Suppose the length of time cats sleep.....

Question

Suppose the length of time cats sleep each day is normally distributed with a mean of 15 hours and a standard deviation of 2 hours. Which group describes 16% of the cat population?

Select each correct answer.

 

cats that sleep more than 17 hours a day

cats that sleep less than 13 hours a day

cats that sleep more than 19 hours a day

cats that sleep less than 11 hours a day

Answer 1

Quan,

 

Use a normal table to find 16%.

z = 0.105 if we want a less than value or

z = 0.995 if we want a greater than value

 

Calculate Z = (x-μ)/σ

x is the unknown

μ = 15

σ  = 2

for each z and solve for x

 

 

.105 = (x-15)/2

.21 = x-15

x = 15.21

Cats sleep <15.21 hours a day

 

,995 = (x-15)/2

1.99 = x-15

16.99 = x

Cats sleep more than 17 hours a day <-------