Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric.

Weights (in lb) of pro football players:x₁;n₁=21 247 261 254 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 272

Weights (in lb) of pro basketball players:x₂;n₂=19

205 200 220 210 192 215 222 216 228 207 225 208 195 191 207 196 181 193 201

(a) Use a calculator with mean and standard deviation keys to calculatex₁,s₁,x₂, ands₂. (Round your answers to four decimal places.)

x₁=

s₁=

x₂=

s₂=

(b) Let₁be the population mean forx₁and let₂be the population mean forx₂. Find a 99% confidence interval for₁₂.(Round your answers to one decimal place.)

lower limit=

upper limit=