Question

i need this question answered

The viscosity of a liquid detergent is supposed to average 705 centistokes at 20 ^oC. A random sample of 5 batches of detergent is collected, and the average viscosity is 720. Suppose we know that the standard deviation of viscosity is σ= 25 centistokes. Find a 92 percent confidence interval on the mean.

Lower Limit = ____________

Upper Limit = ____________

Answer 1

we want to construct the 95% C.I for mean

Given that

Sample mean

Population SD

Sample size = n = 5

Confidence level = C = 0.92

95% C.I for mean is

Where ,

Zc = Critical value for C = 1.751 ..............( From Z table)

95% C.I for mean is

....................( ANSWER)

Lower Limit = 700.427 and

Upper Limit = 739.573

Therefor, 92 percent confidence interval on the mean viscosity of a liquid detergent is .....................( ANSWER)