use Descriptive, inferential, and analytical statistics

1. The Delhi police are interested in determining the average speed of automobiles traveling on the Delhi-Agra Highway. To accomplish this task, the speed of every tenth car passing a particular point on the Delhi-Agra highway is recorded.

a. What is the population for this study?

b. What constitutes the sample?

c. Is speed a categorical or a quantitative variable?

d. If speed is categorical, what type of categorical? If speed is quantitative, what type of continuous?

e. What type of measurement scale is used?

2. A recent study reported the percentage of people 18 years of age and older who play football. Suppose that a study designed to collect new data on footballers and non-footballers uses a preliminary estimate of the proportion who play football of 0.30.

1. How large a sample should be taken to estimate the proportion of footballers in the population with a margin of error of .02? Use 95% confidence.
2. Assume that the study uses your sample size recommendation in part (a) and finds 520 footballers. What is the point estimate of the proportion of footballers in the population?
3. What is the 95% confidence interval for the proportion of footballers in the population?

3. Fifty percent of citizens believed the country was in a recession, even though technically the economic indicators have not yet confirmed this observation. For a sample of 20 citizens, make the following calculations.

1. Compute the probability that exactly 12 people believed the country was in a recession.
2. Compute the probability that no more than five people believed the country was in a recession.
3. How many people would you expect to say the country was in a recession?
4. Compute the variance and standard deviation of the number of people who believed the country was in a recession.