Question

A hypothesis will be used to test that a population mean equals 9 against the alternative that the population mean is less than 9 with known variance . What is the critical value for the test statistic for the significance level of 0.020

Answer 1

-2.05

Explanation:

From the given information,

Let consider
`\mu` to represent the population mean

Therefore,

The null and alternative hypothesis can be stated as :

`H_o :\mu=9`

`H_1 :\mu<9`

From the hypothesis , the alternative hypothesis is one tailed (left)

when the level of significance = 0.020, the Z- critical value can be determined from the standard normal distribution table

Hence, the Z-critical value at ∝ = 0.020 is -2.05