An Experimental Diet to Induce Weight Loss Was Followed for One

An experimental diet to induce weight loss was followed for one week by a randomly selected group of 12 students with the following results.
$\begin{array}{cc}\text { student }&\text { Loss in Pounds }\\1 & 2.2 \\2 & 2.6 \\3 & 0.4 \\4 & 2.0 \\5 & 0.0 \\6 & 1.8 \\7 & 5.2 \\8 & 3.8 \\9 & 4.2 \\10 & 3.8 \\11 & 1.4\\12&2.6\end{array}$
a. Find a point estimate for the average amount lost after one week on this diet. Is this an unbiased estimate of the population mean? Explain.
b. Find a point estimate for the variance of the amount lost on this diet. Is this an unbiased estimate of the population variance? Explain.
c. Find a point estimate for the standard deviation of the amount lost on this diet.