Question

1. A machine is programmed to produce tennis balls so that the mean bounce is 36cm when the ball is dropped from a platform. An experiment is conducted using 35 tennis balls. The 5% level of significance is to be used to test the hypothesis. The sample mean was computed to be 35.5 cm and the standard deviation of the sample is 0.9 cm. Is there evidence that the sample mean is less than 36 cm?

Answer 1

Solution :

= 36

=35.5

S =0.9

n = 35

This is the left tailed test .

The null and alternative hypothesis is ,

H0 :    = 36

Ha : < 36

Test statistic = t

= ( - ) / S / n

= (35.5 - 36 ) / 0.9 / 35

= -3.287

Test statistic = t= -3.287

P-value = 0.0012

= 0.05  

P-value <

0.0012 < 0.05

Reject the null hypothesis .

There is sufficient evidence to suggest that