Question

Individuals working in executive roles within companies are often sleep deprived. A particularly tired vice president of sales begins to track her hours of sleep using a monitoring wrist device. Suppose that the number of hours of sleep she got over the next 5 days was:

4, 9, 6, 7, 5

Assume these days are a representative sample of her typical sleeping habits.

(a)

Identify n.

n =

(b)

Calculate the standard deviation (in hours) of the sample. (Round your answer to four decimal places.)

s =  hr

(c)

Calculate the standard error (in hours) of the point estimate. (Round your answer to three decimal places.)

hr

(d)

Calculate the margin of error (in hours) of the point estimate. Use a 95% confidence level. (Use a table or technology. Round your answer to two decimal places.)

hr

Answer 1

a)

n=5

b)

standard deviation =1.9235

c)

standard error =s/√n =1.9235/√4 =0.962

d)

for 95% CI; and 3 df, critical t=		3.1820
margin of error E=t*std error                            =		3.06