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.

I got D, but not sure if its right.

Question

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.

I got D, but not sure if its right.

agent0smith · Answer

Be sure :)

agent0smith · Answer

More will last closer to 10 years, less will break after a month.... so more will be distributed near the mean (this lowers SD)