7. **Correct. The
answer is true.**

(a) 95% confidence interval is
given by _{}and _{}.

For v=200-1=199 degrees of freedom, find

_{}

_{}

Therefore, _{} and _{}

Then the 95% confidence limits are_{} and
_{}hours
respectively.

(b) 99% confidence interval limits
are given by _{}and _{}.

For v=200-1=199 degrees of freedom, find

_{ }

_{ }

_{}

Therefore, _{} and _{}

Then the 99% confidence limits are _{}and _{} hours respectively.