Finite math

Question

Suppose the weight of an nfl linebacker is normally distributed with a mean of 320 lbs. and a standard deviation of 10.4 lbs. find the pr that the line man weighs at least 300 lbs use z score chart. 

Answer 1

Calculate z: z = 300 -320/10.4 = -20/10.4 = -1.92

 

since at least means greater than or equal to, we need to find the area above the score.

 

the area above = 1-area below

the area below is found in the table of normal distribution

 

so pr(weight>300)=pr(z>-1.92) = 1 - .0274 =.9726