Y or N questions:

1.When the variance of a population is unknown, we sometimes use the z distribution to form a confidence interval of the mean

2. A confidence interval can be widened by decreasing the sample size

3. In a regesssion problem, if we predict a value of y at a given x, its confidence interval will be wider than that of the equation at the same value of y

4. In hypothesis testing the probability of not rejecting a false hypothesis will increase with the sample size

5. The Chi Square distribution is the sum of the square of F distributions

6. As the variance of the dependent variable increases with the independent variable, the regression equations become less reliable in making predictions

7. You are very interested whether a specific pressure will burst a gas container because you have specified that as an allowable pressure. You conduct an experiment applying that pressure to a number of containers. Your Ho hypothesis is that it will not burst.

8. To determine the standard deviation of a distribution that is the sum of a number of distributions, we sum the standard deviations of the distributions

9. The wider a confidence interval is, the less confidence we have that it containes the true value

10. In regession, the variance of the error at the minimumvalue of x is assumed to be smaller than at the maximm value of x

11. We conduct a pairwise comparison because it always gives us a lower p value than the unpaired comparison

12. Decreasing will shorten a confidence interval