Question

The U.S. Dairy Industry wants to estimate the mean yearly milk consumption. A sample of 12 people reveals the mean yearly consumption to be 56 gallons with a standard deviation of 16 gallons. Assume the population distribution is normal. (Use t Distribution Table.)

a. What is the value of the population mean?

b. What is the best estimate of this value?

c. For a 99% confidence interval, what is the value of t?

Answer 1

Solution :

Given that,

a) - E < < + E

b)

Point estimate = = 56

s = 16

n = 56

c)

Degrees of freedom = df = n - 1 = 56 - 1 = 55

At 99% confidence level the t is ,

= 1 - 99% = 1 - 0.99 = 0.01

/ 2 = 0.01 / 2 = 0.005

t _/2,df = t_0.005,55 = 2.668

value of t = 2.668