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

A.) the data is clustered around a central value (mean), with fewer data points towards the edges

B.) from statistical software ...
mean = 195.5 , s.d. = 18.33

231 lbs is 1.94 s.d. above the mean
[(231 - 195.5) / 18.33]
this represents 2.6% of the population
.026 * 218 = 5.67 >>> 6 players

C.) 35 / 218 = .16
this is the fraction of the population below 0.9 s.d. below the mean
195.5 - (0.9 * 18.33) ≅ 179 lbs