A pharmaceutical company claims that its antacid formula provided relief for $70 %$ of all the people who used it. To investigate this claim, a research company randomly selects 81 people who used the company's antacid formula. Source: Sharpe, N.R., De Veaux, R.D. \& Vallemann, P.F. (2015). Business Statistics (3rd edition). Boston, MA: Pearson. a) Describe the shape and report the mean and standard error of the sampling distribu tion of sample proportion of people who got relief by using the company's antacid formula for a sample of size 81 . Report your answer to 4 decimal places. (6 points total, 2 points each) Describe shape: $\mu_{\hat{p}}=$ $\sigma_{\hat{p} }=$ SP.VS. 844