I'm a bit stuck. I need a clear explanation and answer

3. A group of 27 adult men had their weights taken. The list is below. 158 163 169 171 173 177 180 181 184 185 186 189 189 189 193 196 197 197 197 199 202 204 208 211 219 233 255 a) Construct a 90% confidence interval estimate of the mean of the weights. Round the values to one decimal place. mean - 1/2 (158 + 163 . X = 192. 77 2 = b) Construct a 98% confidence interval estimate of the mean of the weights. Round the values o one decimal place