1.Think about confidence intervals: (1 point)

a.Suppose you compute a confidence interval with a sample size of 25. What will happen to the confidence interval if the sample size increased to 50?

b.Suppose you compute a confidence interval of 99% What will happen to the confidence interval if you decrease the confidence level to 90%

2.What are the characteristics of thenormaldistribution?(2 point)

1. What is a Type I error? What is a Type II error?(1 point)

1. What are the characteristics of thebinomialdistribution?(1 point)

1. What is the p-value? What is the level of significance?(1 point)

1. In Germany 75% of homes use heating oil. If eight homes are randomly selected, what is the probability that exactly six will use heating oil?(2 point)

1. A reporter wants to know how Americans feel about politicians and the economy. From a random sample of 2100 Americans 1386 believe that politicians have contributed greatly to our current economic situation. At the 5% level of significance is the proportion of Americans that think politicians have contributed greatly to our currrent economic situation more than 65%? (15 points)

a.State the hypotheses.

b.What is the test statistic?

c.What is the p-value?

d.Make a decision. (Conclusion)

e.Interpret your results.

8.The director of a car factory wants to know the mean daily production. The following is a sample of the number of cars produced at the factory for 10 randomly selected days. (10 points)

61, 54, 59, 65, 63, 57, 35, 48, 60, 55

a)Find the 90% confidence interval for the mean daily production at the car factory.

b)Interpret the confidence interval.