1. If we increase the level of confidence holding all other data constant the range of the interval estimate decreases. True or False

2. The t-distribution is used to develop a confidence interval estimate of the population proportion when the population standard deviation is unknown. True or False

3. Which of the following would be an appropriate alternative hypothesis?

1. The mean of a population is equal to 55.

2. The mean of a sample is equal to 55.

3. The mean of a population is greater than 55.

4. The mean of a sample is greater than 55.

4. When we use separate-variance t-test for the difference between two independent population means U(1) and U(2). We do not have to use a shared degree of freedom to find the value of t a/2. True or False