Team batting averages for major league baseball in 2005 are represented below. Find the variance and standard

Question:

Team batting averages for major league baseball in 2005 are represented below. Find the variance and standard deviation for each league. Compare the results.
NL AL
0.252–0.256 4 0.256–0.261 2
0.257–0.261 6 0.262–0.267 5
0.262–0.266 1 0.268–0.273 4
0.267–0.271 4 0.274–0.279 2
0.272–0.276 1 0.280–0.285 1
Find the variance and standard deviation.