Question

PLEASE HELP

The weight of a soccer ball is normally distributed with a mean of 0.43 kg and a standard deviation of 0.01 kg. Suppose 800 different soccer balls are in a warehouse. About how many soccer balls weigh more than 0.45 kg?
A. 12
B. 20
C. 24
D. 40

Answer 1

Answer is b) 20.

Explanation:

Mean is 0.43 kg.

0.43+0.1+0.1= 0.45

0.45 is two standard deviation above.

All that are below mean is 50%,

Two standard deviation above is 95%/2=47.5%

50%+47.5% =97.7% are balls that are less than 0.45 kg.

100%-97.7%=2.5% balls that are more than 0.45 kg

2.3%=0.025

800*0.025 = 20 soccer balls weigh more than 0.45 kg