The number of cars waiting in line at a car wash is distributed as follows:

Number of Cars           Probability
0...................................................0.25
1...................................................0.40
2...................................................0.20
3...................................................0.10
4...................................................0.04
5...................................................0.01

You can use a table of random numbers (Table E.1) to select samples from this distribution by assigning numbers as follows:

1. Start in the row corresponding to the day of the month in which you were born.

2. Select a two-digit random number.

3. If you select a random number from 00 to 24, record a length of 0; if from 25 to 64, record a length of 1; if from 65 to 84, record a length of 2; if from 85 to 94, record a length of 3; if from 95 to 98, record a length of 4; if 99, record a length of 5.

Select samples of n = 2, n = 15, and n = 30. Compute the mean for each sample. For example, if a sample of size 2 results in the random numbers 18 and 46, these would correspond to lengths 0 and 1, respectively, producing a sample mean of 0.5. If each student selects five different samples for each sample size, a frequency distribution of the sample means (for each sample size) can be developed from the results of the entire class. What conclusions can you reach concerning the sampling distribution of the mean as the sample size is increased?