CH.3
The numerical measure that reveals only the direction of the linear relationship between two variables, but not the strength of the linear relationship, is referred to as the ______.
covariance
A negative skewness coefficient implies that extreme observations are concentrated in the ___ tail of a distribution
left
What is the most widely-used measure of central location?
mean
A positive skewness coefficient implies that extreme observations are concentrated in the____tail of the distribution
right
The notation /x represents the ______. Multiple choice question.
sample mean
The function to find the mean of a subset in R is
tapply
The range is the difference between
the largest and the smallest values.
The median is defined as
the middle value of a data set.
Which of the following is not a measure of central location? Median Mean Weighted mean Variance Mode
variance
A _____ mean is used to calculate the mean of a frequency distribution.
weighted
The term central______ ________ relates to the way data tend to cluster around some middle or central value.
central location
The _____ is not considered a good measure of dispersion because it focuses solely on the extreme values and ignores every other observation in the sample or the population.
range
The pth percentile divides a variable into two parts. What percentage is less than p?
p
The first step to determine the median is to
place the data in numerical order.
The notation μ represents the ______.
population mean
If the covariance between two random variables x and y is positive, then x and y have a(n) _____.
positive linear relationship
Henry's score on an accounting exam placed him in the 85th percentile in the class. What percentage of students scored higher than Henry? Multiple choice question.
15%
The pth percentile divides a variable into two parts. What percentage is greater than p?
(100-p)
A skewness coefficient of ____ indicates the observations are evenly distributed on both sides of the mean.
0
If the median price for a home is $200,000, then ______ of the homes cost less than $200,000.
50%
The function to find the mean of a subset in Excel is
=averageif
The _____ _____is the primary measure of central location.
Arithmetic mean
The owner of BevaMart wants to study the relationship between the outside temperature and hot chocolate sales. The owner computed the covariance between outside temperature and hot chocolate sales to be -81.46. Based on the covariance, which option best describes the linear relationship between temperature and hot chocolate?
As the temperature increases, hot chocolate sales decrease.
When a mean is calculated and some observations are given greater importance than others, we refer to this measure of central locati
Weighted mean
When a mean is calculated and some observations are given greater importance than others, we refer to this measure of central location as a ______. Multiple choice question.
Weighted mean
In order to calculate the arithmetic mean, one
adds all of the data points, then divides by the number of data points.
