Question

A test of the null hypothesis

H₀: μ = μ₀

gives test statistic

z = −1.24.

(Round your answers to four decimal places.)

(a) What is the P-value if the alternative is

H_a: μ > μ₀?

(b) What is the P-value if the alternative is

H_a: μ < μ₀?

(c) What is the P-value if the alternative is

H_a: μ ≠ μ₀?

Answer 1

Solution :

Given that,

z = - 1.24

Using standard normal table,

p value = 0.1075

a ) P(z > - 1.24 )

This is the right tailed test .

   1 - P(z < - 1.24)

= 1 - 0.1075

= 0.8925

P-value = 0.8925

Reject the null hypothesis .

b ) P(z < - 1.24) = 0.1075

This is the left tailed test .

Do not reject the null hypothesis .

c ) This is the two tailed test ,

Using standard normal table,

P-value = 2 * P(z > 2.58)

               = 2 * 0.8925

               = 1.785

P-value = 1.785

Reject the null hypothesis