SOLUTION: Please help me solve this equation. It is Hypothesis testing. The question is as follows: The Nero Match Company sells matchboxes that are supposed to have an average of 45 matches

Algebra ->  Probability-and-statistics -> SOLUTION: Please help me solve this equation. It is Hypothesis testing. The question is as follows: The Nero Match Company sells matchboxes that are supposed to have an average of 45 matches      Log On


   

Question 1171909: Please help me solve this equation. It is Hypothesis testing. The question is as follows: The Nero Match Company sells matchboxes that are supposed to have an average of 45 matches per box, with 𝜎 = 12. A random sample of 94 Nero matchboxes shows the average number of matches per box to be 42.1. Using a 5% level of significance, can you say that the average number of matches per box is different from 45?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Ho: M=45
Ha: M NE 45
alpha=0.05 P{reject Ho|Ho true}
test is a z
critical value |z| >1.96
calculation z=(x bar-mean/sigma/sqrt(n)
z=-2.9*sqrt(94)/12
=-2.34
this is outside the range of Ho (less than -1.96)
reject Ho--we conclude the average number of matches per box is not 45 but fewer.
p-value is 0.019.