Question

previous test:  

Average was 92.84

New test:

n= 40 baseballs

mean: 92.67

Std Deviation: 1.8 inches

Ha: µ≠ 92.84

confidence significance level: 0.10

a). What is the critical reject region?

b.) If the numerator of the test statistic is 92.67-92.84 what is the value of the denominator?

Answer 1

Solution :

This is the two tailed test .

The null and alternative hypothesis is ,

H₀ :   = 92.84

H_a :    92.84

Test statistic = z

= ( - ) / / n

= (92.67 - 92.84) /1.8 / 40    value of the denominator = 1.8 / 40

= -0.60

Test statistic = -0.60

= 0.10

/ 2 = 0.10 / 2 = 0.05

Z_/2 = Z _0.05 = 1.645

Rejection region : z < -1.645 or z > +1.645