Question

A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 447 gram setting. It is believed that the machine is overfilling the bags. A 31 bag sample had a mean of 455 grams. Assume the population variance is known to be 900. Is there sufficient evidence at the 0.1 level that the bags are overfilled? Step 4 of 6: Find the P-value of the test statistic. Round your answer to four decimal places.

Answer 1

Solution :

The null and alternative hypothesis is ,

H0 :   = 447

Ha : > 447

Test statistic = z

= ( - ) / / n

= (455 - 447) / 30 / 31

= 1.48

This is the right tailed test,  

P(Z > 1.48) = 1-P (Z < 1.48 ) = 1 - 0.9306

P-value = 0.0694

= 0.1

P-value <

Reject the null hypothes