Question

PLEASE HELP me ANSWER these!!! My grade depends on it!!

Last year the number of skateboards produced per day at a certain factory were normally distributed with a mean of 20,500 and a standard deviation of 55 skateboards. Answer the following.
On what percent of days last year did the factory produce 20,555 skate boards or fewer?

On what percent of days last year did the factory produce 20,610 skateboards or more?

On what percent of days last year did the factory produce 20,445 skate boards or fewer?
On

Answer 1

M (Mean) = 20,500;
SD (Standard Deviation) = 55
1 ) 20,555 = 20,500 + 55 = M + 1 SD
Answer: 50% + 34.1% = 84.1%
2 ) 20.610 = 20,000 + 110 = M + 2 SD
Answer: 10% - ( 50% + 34.1% + 13.6% ) = 100% - 97.7% = 2.3%
3 ) 20,445 = 20,500 - 55 = M - 1 SD
Answer: 50% - 34.1% = 15.9%