Question

Can someone help with with question 4 part B and D

c. over $90? Question 3. An industrial crane is operated by four electric motors working together For the crane to perform properly, the four motors have to generate a total of at least horsepower. Engineers from the plant that produces the electric motors have stated that motors off their assembly line average 100 horsepower, with a standard deviation of lo horsepower. The four electric motors on the crane have just been replaced with four band new motors from the motor manufacturer. A safety engineer is concerned that the four motors might not be powerful enough to properly operate the crane. Stating any additional assumptions you are using, does the engineer's concern appear to be justified? Question 4. It has been estimated that 17% of mutual fund shareholders are retired persons. Assuming the population proportion to be sample of 400 shareholders has been selected: .17, and that a simple random What is the expected value of p- the proportion of those in the sample who are retired? What is the standard error of the sampling distribution of the proportion, p? What is the probability that at least 20% of those in the sample will be retired? What is the probability that between 15% and 25% of those in the sample will be retired?

Answer 1