beep bop lip lop bizzzzoppppppp

The cutoff for defining a large correlation is 0.5.

False

The filters field of a pivot table contains the data that you want summarized.

False

. A trend line on a scatterplot is a line or a curve that "fits" the scatter as well as possible

True

An example of a joint category of two variables is the count of all non-drinkers who are also nonsmokers

True

Which Excel® function allows you to count using more than one criterion?

b. COUNTIFS

What does a scatterplot illustrate?

b. What type of relationship there is between two variables

A line or curve superimposed on a scatterplot to quantify an apparent relationship is known as a(n)

b. trend line.

38. Which of the following are considered numerical summary measures?

c. Correlation and covariance

. The limitation of covariance as a descriptive measure of association is that it

c. is very sensitive to the units of the variables.

44. The tables of counts that result from pivot tables are often called

d. crosstabs.

Correlation and covariance can be used to examine relationships between numeric variables as well as for categorical variables that have been coded numerically

False

If the standard deviation of X is 15, the covariance of X and Y is 94.5, and the correlation is 0.90, then the variance of Y is 7.0.

Fizalse

Beep?

Bop.

. If the coefficient of correlation r = 0 .80, the standard deviations of X and Y are 20 and 25, respectively, then Cov(X, Y) must be 400.

Trizue

Side-by-side box plots allow you to quickly see how two or more categories of a numerical variable compare.

True

. Scatterplots are also referred to as

c. X-Y charts.

7. Correlation is useful only for

c. measuring the strength of a linear relationship.

Correlation and covariance measure the

c. strength and direction of a linear relationship between two numerical variables.

The most common data format is

c. stacked

Which correlation coefficient suggests the strongest relationship?

+1

. To examine relationships between two categorical variables, we can use

A - counts and corresponding charts of the counts.

Correlation is affected by the measurement scales applied to the X and Y variables.

False

Relationships between two variables are less evident when counts are expressed as percentages of row totals or column totals.

False

We can use side-by-side boxplots to compare at most 2 distributions of numeric data.

False

We cannot attempt to interpret correlations numerically, with the one possible exception of indicating whether they are positive or negative.

False

Comparing a numerical variable across two or more subpopulations is known as a comparison problem.

True

Correlation is a single-number summary of a scatterplot.

True

Correlation is not useful for describing the strength and direction of nonlinear relationships.

True

Counts for a categorical variable are often expressed as percentages of the total.

True

If the standard deviations of X and Y are 15.5 and 10.8, respectively, and the covariance of X and Y is 128.8, then the correlation coefficient is approximately 0.77.

True

Statisticians often refer to the pivot tables that display counts as contingency tables or crosstabs.

True

Strongly related variables may have a correlation close to zero if the relationship is nonlinear.

True

The advantage that correlation has over covariance is that correlation has a set lower and upper limit.

True

The correlation between two variables is unitless and always between -1 and +1

True

The scatterplot is a graphical technique used to display the relationship between two numerical variables.

True

To form a scatterplot of X versus Y, X and Y must be paired variables

True

. We can infer that there is a strong relationship between two numeric variables when the points on a scatterplot

a. cluster tightly around a straight line.

45. The four areas of a pivot table are

c. Filters, Rows, Columns, and Values.

A useful way of comparing the distribution of a numerical variable across categories of some categorical variable is with

c. a side-by-side plot or side-by-side pivot table.

Displaying all correlations between 0.6 and 0.999 on a scatterplot as green and all correlations between -1.0 and -0.6 as red is known as _____ formatting.

c. conditional

39. One characteristic of "paired variables" is that

c. each variable has the same number of observations.

Tables used to display counts of a categorical variable are called

c. either crosstabs or contingency tables.

The tool that provides useful information about a data set by breaking it down into categories is a

c. pivot table.

. Examples of comparison problems include

d. all of these choices.

We study relationships among numerical variables using

d. percentages.

46. Changing the location of fields in a pivot table is known as

d. pivoting.

. If the correlation of variables is close to 0, then we expect to see a(n) _____ on the scatterplot.

d. random scatter of points with no apparent relationship