Question

Good-Buy Electronics: You own a branch of Good-Buy Electronics and have been told by the manufacturer of Stevuski Televisions that only 5% of their brand of TVs die within one year. Last year, your branch sold 148 such televisions in July. One year later, 12 (about 8%) of them had been returned — dead.

(a) Assuming the 5% value quoted by the manufacturer was accurate, what is the mean number of TVs that die within one year in randomly samples of size 148? Round your answer to one decimal place.
μ =

(b) What is the standard deviation? Round your answer to one decimal place.
σ =

(c) You had 12 TVs die out of 148 (about 8%). With respect to the mean and standard deviation found in parts (a) & (b) respectively, what is the z-score for this many dead TVs? Round your answer to two decimal places.
z =

(d) Assuming the 5% rate is accurate, would 12 dead TVs in a sample of 148 TVs be considered unusual?

Yes, that is an unusual number of dead TVs.No, that is not unusual.   

Answer 1