Exam 4: A: Numerical Descriptive Techniques

Weights of Workers The following data represent the number of employees of a sample of 25 companies: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171. -{Weights of Workers Narrative} Is the distribution of the number of workers symmetric or skewed? Why?

Weights of Workers The following data represent the number of employees of a sample of 25 companies: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171. -{Weights of Workers Narrative} Find the mean number of workers.

Ages of Retirees A sociologist recently conducted a survey of retirees over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 20 uninsured retirees were as follows: 65,66,67,68,69,70,71,73,74,75,78,79,80,81,86,87,91,92,94,and 97. -{Ages of Retirees Narrative} Calculate the third quartile of the ages of the uninsured retirees.

Percentiles can be converted into quintiles and deciles,where quintiles divide the data into fifths,and deciles divide the data into tenths.

The mean of a sample of 15 measurements is 35.6 feet.Suppose that the sample is enlarged to 16 measurements,by including one additional measurement having a value of 42 feet.Find the mean of the sample of the 16 measurements.

In a histogram,the proportion of the total area which must be to the left of the median is less than 0.50 if the distribution is negatively skewed.

Ages of Senior Citizens A sociologist recently conducted a survey of citizens over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 22 uninsured senior citizens were as follows: 65,66,67,68,69,70,71,73,74,75,76,77,78,79,80,81,86,87,91,92,94,and 97. -{Ages of Senior Citizens Narrative} Calculate the median age of the uninsured senior citizens.

If two data sets have the same range,the distances from the smallest to largest observations in both sets will be the same.

If the first and second quartiles are closer to each other than are the second and third quartiles,then the shape of the histogram based on the quartiles is ____________________.

The coefficient of variation allows us to compare two sets of data based on different measurement units.

Which of the following statements is true regarding the data set 8,8,8,8,and 8?

If the first and second quartiles are farther apart than the second and third quartiles,then the shape of the histogram based on the quartiles is ____________________.

If a data set contains an even number of observations,the median is found by taking the ____________________ of these two numbers.

If the distribution of a data set were perfectly symmetric,the distance from Q₁ to the median would always equal the distance from Q₃ to the median in a box plot.

Ages of Jockeys The following data represent the ages in years of a sample of 25 jockeys from a local race track: 31,43,56,23,49,42,33,61,44,28,48,38,44,35,40,64,52,42,47,39,53,27,36,35,and 20. -{Ages of Jockeys Narrative} Find the lower quartile of the ages.

The first and second quartiles of a data set can never be equal.

While Chebysheff's Theorem applies to any distribution,regardless of shape,the Empirical Rule applies only to distributions that are bell shaped.

Which measures of central location and variability are considered to be resistant to extreme values?

According to Chebysheff's Theorem,at least 93.75% of observations should fall within 4 standard deviations of the mean.

____________________ are extremely large or extremely small observations.