Question

Help!


100 AAA batteries were tested on a particular MP3 player. Suppose the battery has a mean lifetime of 31.7 hours, with a standard deviation of 2.9 hours. How long do we expect the majority of batteries to last?
A. Between 2.9 and 31.7 hours
B. Between 28.8 and 31.7 hours
C. Between 31.7 and 34.6 hours
D. Between 28.8 and 34.6 hours

Answer 1

I know its not A.

Answer 2

What's your best guess and why? I have a feeling you intuitively already know.

Answer 3

i would say d

Answer 4

well, what i did was i took 31.7+2.9 and then divided by 2, and got my answer 17.3, but got that wrong, so i would say D, is my best answer, do u guys both agree?

Answer 5

@Kainui