Exam 4: Numerical Descriptive Techniques

The y-intercept of the least squares line is the point on the line where ________________ = 0.

There are three statistics used to measure variability in a data set; the range, the ____________________ and the ____________________.

The range, variance, standard deviation, and coefficient of variation are to be used only on ____________________ data.

The method used to find the best fitting line through the observations is called the ____________________ method.

NARRBEGIN: Weights of Police Officer Weights of Police Officers The following data represent the weights in pounds of a sample of 25 police officers: 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 Police Officers Narrative} What does the histogram tell you about the distribution of the weights of workers?

NARRBEGIN: Experience and Salary Longevity and Salary A sample of eight observations of variables x (years of experience) and y (salary in $1,000s) is shown below: 5 3 7 9 2 4 6 y 20 23 15 11 27 21 17 14 NARREND -{Longevity and Salary Narrative} Draw the scatter diagram and plot the least squares line.

NARRBEGIN: Strip Mall Rent Strip Mall Rent Monthly rent data in dollars for a sample of 10 stores in a small town in South Dakota are as follows: 220, 216, 220, 205, 210, 240, 195, 235, 204, and 250.NARREND -{Strip Mall Rent Narrative} Compute the sample monthly average rent.

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

Which of the following statistics is a measure of central location?

When extreme values are present in a set of data, which of the following descriptive summary measures are most appropriate?

The ____________________ is the square root of the ____________________.

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} Compute and compare the coefficient of variation for the three samples.

The coefficient of determination is the percentage of variation in the ____________________ variable that is explained by the variation in the ____________________ variable.

Lily has been keeping track of what she spends to eat out. The last week's expenditures for meals eaten out were $5.69, $5.95, $6.19, $10.91, $7.49, $14.53, and $7.66. The mean amount Lily spends on meals is $8.35.

NARRBEGIN: Milk Demand Milk Demand A supermarket has determined that daily demand for milk containers has an approximate bell shaped distribution, with a mean of 55 containers and a standard deviation of six containers.NARREND -{Milk Demand Narrative} What percentage of the time will the number of containers of milk sold be more than 2 standard deviations from the mean?

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} Find the median hours.

The ____________________ of the correlation indicates the direction of a linear relationship.

If two data sets have the same standard deviation, they must have the same coefficient of variation.

A data sample has a mean of 107, a median of 122, and a mode of 134. The distribution of the data is positively skewed.

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} Find the mean number of workers.