Question

A sample of 65 electric motors had a mean efficiency of 0.595 with a standard deviation of 0.05. Let μ represent the mean efficiency of electric motors of this type.

Find the P-value for testing H₀ : μ ≥ 0.6 versus H₁ : μ < 0.6.

Answer 1

Solution :

= 0.60

= 0.595

s =0.05

n = 65

This is the left tailed test .

The null and alternative hypothesis is

H0 :   ≥ 0.60

Ha : < 0.60

Test statistic = t

= ( - ) / s / n

= (0.595 -0.60) / 0.05 / 65

= -0.806

P (t< -0.806 ) = 0.2101

P-value = 0.2101