In: Statistics and Probability
The quality-control manager at a compact fluorescent light bulb (CFL) factory needs to determine whether the mean life of a large shipment of CFLs is equal to 7,476 hours. The population standard deviation is1,080 hours. A random sample of 81 light bulbs indicates a sample mean life of 7,176 hours.
a. At the0.05 level of significance, is there evidence that the mean life is different from 7,476 hours?
b. Compute the p-value and interpret its meaning.
c. Construct a 95% confidence interval estimate of the population mean life of the light bulbs.
d. Compare the results of (a) and (c). What conclusions do you reach?
A. Let μbe the population mean. Determine the null hypothesis, H0, and the alternative hypothesis, H1.
What is the test statistic?
What is/are the critical value(s)?
What is the final conclusion?
B. What is the p-value? Interpret the meaning of the p-value.
C. Construct a 95% confidence interval estimate of the population mean life of the light bulbs.
D. Compare the results of (a) and (c). What conclusions do you reach?