Exercise 1

Calculate a four-quarter weighted moving average for the number of America Online (AOL) subscribers for the nine quarters of data. The data are reported in thousands. Apply weights of .1, .2, .3 and .4, respectively, for the quarters. In a few words, describe the trend in the number of subscribers.

31-Mar-01 28,766

30-Jun-01 30,057

30-Sep-01 31,336

31-Dec-01 33, 240

31-Mar-02 34,610

30-Jun-02 35,102

30-Sep-02 35,308

31-Dec-02 35,203

31-Mar-03 34,386

Part II

1. Define:

Statistics

Hypothesis

Parameter

2. In a particular market there are three commercial television stations, each with its own evening news program from 6:00 to 6:30 P.M. According to a report in this morning's local newspaper, a random sample of 150 viewers last night revealed 53 watched the news on WNAE (channel 5), 64 watched on WRRN (channel 11), and 33 on WSPD (channel 13). At the .05 significance level, is there a difference in the proportion of viewers watching the three channels?

3. A rental company charges $30 a day and 15 cents per mile for renting a car. Let y be the total charges (in dollars) for a car for one day and x be the miles driven. The equation for the relationship between x and y is:
Y = 30 + .15X

How much will a person pay who rents a car one day and drives it 100 miles?
Suppose each of 20 persons rents a car from this agency for one day and drives it 100 miles. Will each of them pay the same amount for renting a car for a day or is each person expected to pay a different amount? Explain.

Is the relationship between X and Y exact or nonexact?

Identify the dependent and independent variables.