how to solve those 3 questions

Review: Given the following multiple regression output from body fat % data: [Bodyfat % is the response What distribution would best model the sampling distribution with a sample proportion of p = .5 variable] and with a sample size of 50? Coefficients Term Coef SE Coef 95% CI T-Value P-Value O normal distribution Constant 49.59 16.81 (16.22, 82.96) 2.95 0.0040 Age 0.16531 0.05022 (0.06561, 0.26500) 3.29 0.0014 O t-distribution Weight 0.22638 0.02275 (0.18122, 0.27154) 9.95