Question

The web-based company Baby! Gifts have a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day, would this prove that they are exceeding their goal, using= 0:025? What is the null hypothesis, decision rule, sample portion, and test statistics?

Answer 1

Solution :

This is the right tailed test .

The null and alternative hypothesis is

H0 : p = 0.95

Ha : p >0.95

n = 500

x =485

= x / n = 485 / 500 =0.97

P0 = 0.95

1 - P0 = 1 - 0.95 = 0.05

Test statistic = z

= - P0 / [P0 * (1 - P0 ) / n]

= 0.97 - 0.95/ [(095 *0.05) / 500 ]

= 2.05

Test statistic = z =2.05

P(z > 2.05 ) = 1 - P(z < 2.05 ) = 1 - 0.9798

P-value = 0.0202

= 0.025

P-value <

0.0202 < 0.025

Reject the null hypothesis .

There is sufficient evidence to suggest that