Since many people have trouble programming their DVD players

Since many people have trouble programming their DVD players, an electronics company has developed what it hopes will be easier instruction: The goal is to have at least 91% of customers succeed at being able to program their DVD players. The company tests the new system on 200 people, 176 of whom were successful. Is this strong evidence that the new system fails to meet the company\'s goal? A student\'s test of this hypothesis is provided. How many mistakes can you find? Click the icon to view the student\'s test of the hypothesis. Identify any mistakes in the student\'s calculation of the P-value. If there are any mistakes, show what the correct calculations for the P-value should be. Choose the correct answer below. The student\'s calculation of SD is incorrect and carries through the calculation of The student\'s calculation of the P-value is correct. The calculation of the probability is incorrect; P = P(z> 1.30) = 0.10 The calculation of the probability is incorrect; P = P(z >1.30) = 0.90 Identify any mistakes in the student\'s conclusion. If there are any mistakes, state what the correct conclusion should be. Assume all requirements for the test are satisfied. Choose the correct answer below. The student\'s conclusion is correct. There is strong evidence that the new system works. There is strong evidence that the new system does not work. There is no evidence that the new system works.

Solution

correct conclusion - there is strong evidence that system does not work

explanation:

a) the student\'s conclusion is not correct - for part c and d because the students calculation of p value is correct

b) there is strong evidence that new system works. No, because the calculation shows pcal<p or 0.07<0.09 (91% confidence level)

d) there is no evidence that new system works - this is also not true because the study shows that out of 200 customers new system worked with 176 customers