Question

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 414 gram setting. It is believed that the machine is underfilling the bags. A 11 bag sample had a mean of 421 grams with a standard deviation of 28. assume the population is normally distributed. a level of signifigance of 0.02 will be used. specify the type of hypothesis test.

left tailed

right tailed

two tailed

Answer 1

Solution :

= 414

=421

= 28

n = 11

This is the right tailed test .

The null and alternative hypothesis is

H0 :   = 414

Ha : > 414

Test statistic = z

= ( - ) / / n

= (421 -414) /28 / 11

= 0.829

p(Z > 0.829) = 1-P (Z <0.829 ) = 0.7964

P-value = 0.7964