Question

# Assume that the average volume of raindrops globally is normally distributed with mean 0.45 ml and...

Assume that the average volume of raindrops globally is normally distributed with mean 0.45 ml and variance 0.01 ml2. Michael measures the volume of two raindrop at Rainyville as 0.65 ml and 0.75 ml; and comes to believe that the raindrops at Rainyville are significantly larger than the global average at the 5% level.

Which statistical test should Michael use and why?

A. The Z-test because population standard deviation is known.

B. The T-test because the population standard deviation is unknown.

C. The Z-test because population standard deviation is unknown.

D. The T-test because population standard deviation is known.

Solution

Given,

= 0.45 (population mean)

= 0.01 (population SD)

Claim by Michel is is significantly greater than 0.45

Hypothesis are

H0: = 0.45 vs H1: > 0.45

Since the population SD is known , we use z test

A. The Z test, because the population standard deviations is known.

(If unknown, then use t test)