Exam 4: Numerical Descriptive Techniques

The range is considered the weakest measure of variability.

We can frequently make several inferences about the nature of the data from the ____________________ of its histogram.

Three measures of the linear relationship between x and y are the coefficient of correlation, the coefficient of determination, and the coefficient of variation.

The difference between the largest and smallest observations in an ordered data set is called the range.

The mean is a measure of variability.

Which of the following summary measures is affected most by extreme values?

NARRBEGIN: Weights of Workers 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.NARREND -{Weights of Workers Narrative} Construct a stem and leaf display for the number of workers.

Which of the following summary measures cannot be easily approximated from a box plot?

Expressed in percentiles, the fifth decile is the 50^th percentile or the median.

Chebysheff's Theorem states that the percentage of measurements in a data set that fall within three standard deviations of their mean is:

NARRBEGIN: Hours Worked per Week Hours Worked per Week The following data represent the hours worked per week of a sample of 25 employees from a government department: 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.NARREND -{Hours Worked per Week Narrative} Compute the sample mean hours.

The line drawn within the box of a box plot always represents the mean.

A popular method of creating distorted impressions with bar charts is to construct the bars so that their widths are proportional to their heights.

Q₂ is another name for the ____________________.

In a negatively skewed distribution, the distance from the smallest observation to Q₁ exceeds the distance from Q₃ to the largest observation.

NARRBEGIN: Ages of Workers Ages of Workers The ages (in years) of three groups of workers are shown below: GROUP A: 17 22 20 18 23 GROUP B: 30 28 35 40 25 GROUP C: 44 39 54 21 52 NARREND -{Ages of Workers Narrative} Calculate and compare the standard deviations for the three samples.