Question

1. As we prepare to discuss confidence levels and make decision, we are using the mean as the bases for our central point. Why are we able to do this and what are some of the parameters we must consider?

2. We discussed confidence levels in Chapter 8 and Hypothesis testing in Chapter 9. What are the common elements of each? When would you use one or the other?

3. Explain when you would use the “z” table to determine distance from the center point on the curve and when you would use the “t” table?

4. Explain what is meant by the sampling error?

Answer 1

1) Confidence level depends on the variability also. But usually researchers set 90%,95%,99% as the confidence level by their previous experience.

2) testing of hypothesis is equivalent to interval estimation but in interval estimation we nave to consider the acceptance region, and find its probability, which is the compliment of rejection region we use in testing of hypothesis.

3)Z test and Z table is used when the sample size is very large and t test and t table is used if sample size is small as well as variance is unknown.

4) It is an error which is the difference between actual and the sample statistic used which is usually happened in estimating a parameter.