In: Statistics and Probability
A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 430 gram setting. It is believed that the machine is overfilling the bags. A 38 bag sample had a mean of 432 grams. Assume the population standard deviation is known to be 29. Is there sufficient evidence at the 0.02 level that the bags are overfilled?
Step 1 of 6:
State the null and alternative hypotheses.
Step 2 of 6:
Find the value of the test statistic. Round your answer to two decimal places.
Step 3 of 6:
Specify if the test is one-tailed or two-tailed.
Step 4 of 6:
Find the P-value of the test statistic. Round your answer to four decimal places.
Step 5 of 6:
Identify the level of significance for the hypothesis test.
Step 6 of 6:
Make the decision to reject or fail to reject the null hypothesis.
Given that a manufacturer of potato chips would like to know whether its bag filling machine works correctly at the = 430 gram setting. It is believed that the machine is overfilling the bags. A n = 38 bag sample had a mean of = 432 grams. Assuming the population standard deviation is known to be = 29.
Step-1
For the given details the hypotheses are:
Step-2:
The test statistic is calculated as:
Z = 0.43
Step-3:
Based on the hypothesis it will be a right-tailed test.
Step-4:
P-value:
The P-value for the calculated test statistic is calculated using excel for normal distribution, the formula is =1-NORM.S.DIST(0.425, TRUE), thus the P-value is 0.3354.
Step-5:
The level of significance is given as 0.02.
Step-6:
Decision:
Since P-value is greater than 0.02 hence we failed to reject the null hypothesis and conclude that there is insufficient evidence to support the claim that the bags are overfilled.