Question

supposed the number of wins team in the nfl have per year is normal with a mean of 11 and standard deviation of 2. what percentage of teams win between 7 and 15 games?

Answer 1

solution:

the mean = = 11

SD. = = 2

we have to find the percentage of team win between 7 and 15 games. = P( 7 < X < 15)

for X = 7, corresponding z score

for X = 15,

P( 7 < X < 15) = (value of z to the left of 2) - (value of z to the left of -2)

   = 0.9772 - 0.0228 = 0.9544 = 95.44%

so, percentage of team win between 7 and 15 games = 95.44%