The Edmonton rush is one of nine teams that play in the national lacrosse league. The weights of the 2013 Edmonton rush players are shown.

Weight in Lbs.
160. 170. 170. 175. 180
185. 188. 190. 190. 190
194. 195. 200. 200. 200
205. 205. 210. 210. 210
210. 215. 245.
A.) Explain why this data is close to being normally distributed.
B.) There were 218 players in the national lacrosse league in 2013. Assuming the mean and standard deviation of the league are same as the mean and standard deviation of the Edmonton rush, predict the number of players that weighed over 231 lbs.
C.) Below what weight should there be approximately 35 national lacrosse league players?

Please help, I have no idea how to do these.

1 answer

B) Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. Multiply by 218.

C) Find Z score probability = 35/218. Insert Z value into above equation.