**Chapter 7**

1. Define bias in terms of expected value.

2. Is it possible for a statistic to be unbiased yet be very inefficient? How
about being very efficient but biased?

3. You know that μ = 10 and sample two numbers. If the two numbers are 6
and 10, what is your best estimate of σ²? How many degrees
of freedom does your estimate have?

4. You do not know m and sample two numbers. If the
two numbers are 6 and 10, what is your best estimate of σ²?
How many degrees of freedom does your estimate have?