Let X bar be the mean of a random sample from the exponential distribution.

a) show that xbar is unbiasedpoint estimator of

b) using the mgf technique,determine the distribution of xbar

c) use (b) to show that Y= 2nx bar/ has x^2 (chi) distibution with 2n degrees of freedom.

d) based on part (c),find a 95 % confidence interval for if n=10