Question

MEDAL! SOMEBODY PLEASE HELP!
A manufacturer makes ceramic heaters that have a life expectancy of 10 years. Two percent of the heaters are defective because they break down after the first month. If the manufacturing process is improved so that the number of defective units drops to 1%, how will the standard deviation of the heaters change?
A.
The effect is unknown.
B.
It will not change at all.
C.
It will increase.
D.
It will decrease.

Answer 1

@Directrix no one is helping me :/

Answer 2

This sounds like the nail problem to me.

Answer 3

i know, but their different probs

Answer 4

If the failure rate drops a percentage point, then the variability will lessen. Standard deviation is square root of variability so I would expect the standard deviation to decrease. I don't know how to quantify that.

Answer 5

@katlin95 Do you know if the answer to that wall nail problem was correct? Because I think this is the same type problem but about a different product.

Answer 6

i will know after im done with my assignment. I got that it decreases as well, so ill let u know after Im done.

Answer 7

Okay. The question is a wee bit vague which is why computation is not possible as far as I see. But, if I were doing the homework, that is the answer I would choose.

Answer 8

you were correct

Answer 9

Okay. Then, the heater and the nail problem should both have the same answer and be correct, I hope. Thanks for telling me because these same problems will come up several months later and knowing the correct reasoning will help out somebody on down the line.