Chapter 3: Descriptive Statistics: Numerical Methods

The mean is a measure of
1. association.
2. location.
3. relative location.
4. variability.
5. None of the above
The correlation coefficient is a measure of
1. association.
2. location.
3. relative location.
4. variability.
5. None of the above
The percentile is a measure of
1. association.
2. location.
3. relative location.
4. variability.
5. None of the above
To summarize a data set with a five-number summary, which of the following is not needed?
1. The first quartile
2. The largest value
3. The mean
4. The median
5. All of the above are needed.
In a graduate class of four students, the grades on the first test were
93 87 62 98
Find the population mean.
1. 85
2. 90
3. 95.5
4. 340
5. None of the above
In a graduate class of four students, the grades on the first test were
93 87 62 98
Find the population standard deviation.
1. 13.84
2. 15.98
3. 191.5
4. 255.33
5. None of the above
A sample of five price/earnings ratios for companies in the Services sector follows.
37 11 14 17 12
Find the sample mean.
1. 10.76
2. 14
3. 18
4. 18.2
5. None of the above
A sample of five price/earnings ratios for companies in the Services sector follows.
37 11 14 17 12
Find the sample standard deviation.
1. 9.62
2. 10.76
3. 11.5
4. 115.7
5. None of the above
A sample of five price/earnings ratios for companies in the Services sector follows.
37 11 14 17 12
Find the sample median.
1. 10.76
2. 14
3. 18
4. 18.2
5. None of the above
A sample of five price/earnings ratios for companies in the Services sector follows.
37 11 14 17 12
Find the first quartile.
1. 9.62
2. 10.76
3. 11.5
4. 12
5. None of the above
A sample of five price/earnings ratios for companies in the Services sector follows.
37 11 14 17 12
In a box plot, which of the observations would be considered an outlier?
1. 11
2. 37
3. Both a and b
4. There are no outliers in this data set.
5. None of the above
If a covariance is negative then, in general, as
1. x increases, y increases
2. y increases, x increases
3. x increases, y increases
4. None of the above
If the covariance is negative, then the sign of the correlation coefficient must be
1. negative
2. positive
3. The sign cannot be determined
The wages of social workers at a large nonprofit agency average $25,000 with a standard deviation of $2000. At least what percentage of social workers earns between $21,000 and $29,000.
1. 68%
2. 75%
3. 89%
4. 95%
5. The answer cannot be determined with the given information.
The wages of social workers at a large nonprofit agency average $25,000 with a standard deviation of $2000. Assuming that the distribution of wages is mound shaped, approximately what percentage of social workers earns between $21,000 and $29,000.
1. 68%
2. 75%
3. 89%
4. 95%
5. The answer cannot be determined with the given information
At a new baseball stadium, seats are priced as follows:

Find the weighted mean price of a seat at the stadium.
1. $15.00
2. $16.67
3. $17.42
4. $18.13