biased estimator

sara_87

1. The problem statement, all variables and given/known data

The reading on a voltmeter connected to a test circuit is uniformly distributed on the interval (a, a+1) where a (unknown) is the true voltage. Let Y1, Y2, Y3,...,Yn denote a random sample of such readings.
show that Y(bar) is a biased estimator for a.
and find an unbiased estimator for a expressed in terms of Y(bar)

2. Relevant equations



3. The attempt at a solution

i have no idea how to do thus question so any help would be v much appreciated.
Thank you