Exam 3: Statistical Description of Data

Salaries The salaries (in thousands of dollars)for a sample of 13 employees of a firm are: 26.5,23.5,29.7,24.8,21.1,24.3,20.4,22.7,27.2,23.7,24.1,24.8,and 28.2. -Compute the mean salary.

If the coefficient of correlation r = 0,then:

For a set of data,the mean is 50 and the standard deviation is 10.In the raw data,one of the observations is equal to 74.After the data are standardized,what will be the standardized value of this observation?

Sample data Consider the following sample data: 6,10,4,3,7,9,21,and 14. -What is the mean absolute deviation?

The Empirical Rule states that the percentage of observations in a data set (providing that the data set has a bell-shaped and symmetric distribution)that fall within one standard deviation of their mean is approximately:

Which of the following statements is correct?

Intervals Let x be the class mark for each of the intervals below. Interval Frequency 0-2 2 3-5 6 6-8 10 9-11 5 12-14 2 -Compute the sample standard deviation for the data above.

When the standard deviation is expressed as a percentage of the mean,the result is the:

If the coefficient of correlation r is negative,the dependent variable y and the independent variable x are said to be ____________________ related.

Salaries The salaries (in thousands of dollars)for a sample of 13 employees of a firm are: 26.5,23.5,29.7,24.8,21.1,24.3,20.4,22.7,27.2,23.7,24.1,24.8,and 28.2. -Compute the standard deviation of the salaries.

The coefficients of correlation and determination are two statistical measures of ____________________.

Measures of dispersion describe typical values in the data.

A survey asked 200 respondents how many children under the age of 18 live in the household.The following table summarizes the results. Number af Children Number af Hausehalds 0 40 1 24 2 62 3 26 4 32 5 16 Tatal 200 Calculate the mean number of children in the distribution.

A company counted the number of their employees in each of the following age classes.According to this distribution,what is the average age of the employees in the company? Age Range Number of Emplayees 20-24 8 25-29 37 30-34 25 35-39 48 40-44 27 45-49 10

Find the range and midrange from these data: 4,8,2,16,12,10,6,and 22. Range = ____________________ Midrange = ____________________

Under what circumstances would the median of a set of data be more representative than the mean of that data?

Sample data Consider the following sample data: 6,10,4,3,7,9,21,and 14. -What is the standard deviation?

When approximating the mean or standard deviation from a frequency distribution,each observation is considered to be located at the ____________________ of its class.

Between 1980 and 1999,constant dollar spending on non-residential construction in the United Year 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 Spending 27.6 30.8 37.8 40.0 36.9 36.0 38.4 35.7 34.7 35.3 Year 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Spending 37.5 33.3 28.0 27.6 28.6 32.2 36.1 35.4 39.4 41.9 Find the quartiles of these data.

Texas Department A monthly report to the Texas Department of Health,division of Water Hygiene,contained the following water production data in thousands of gallons: 5263 5636 5264 4395 6090 5293 4668 5725 5171 4378 5118 5538 4838 5167 5119 5438 6843 5262 4653 5303 5913 4570 5142 5964 6431 4719 5358 6043 4554 5805 -Calculate the interquartile range.