Hello, please help with this question, thank you!

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

247 261 256 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 270

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

205 200 220 210 192 215 223 216 228 207 225 208 195 191 207 196 183 193 201

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

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=

c) Which distribution did you use? Why?

1-The Student'st-distribution was used because₁and₂are known.

2-The standard normal distribution was used because₁and₂are unknown.

3-The Student'st-distribution was used because₁and₂are unknown.

4-The standard normal distribution was used because₁and₂are known.