Deck 3: Descriptive Statistics

Question 1

Statistical measures used to yield information about the centre or the middle parts of a group of numbers are called the measures of central tendency.

Answer 1

True

Question 2

A measure of how peaked the data is, is called kurtosis.

Answer 2

False

Question 3

Box and whisker plots are a slow method to determine skewness.

Answer 3

False

Question 4

The most frequently occurring value in a set of data is called the mode.

Question 5

One of the main uses of a box and whisker plot is to identify outliers.

Question 6

Skewness indicates that a data distribution is symmetrical or asymmetrical.

Question 7

A box and whisker plot is determined from the mean, the smallest and the largest values, and the lower and upper quartile.

Question 8

The sum of the squared deviations from the arithmetic mean, divided by the sample size minus one is called the sample variance.

Question 9

A nonzero value of the skewness indicates asymmetry of the distribution of the data.

Question 10

Average deviation is a common measure of the variability of data containing a set of numbers.

Question 11

The sample standard deviation is calculated by taking the square root of the population standard deviation.

Question 12

Kurtosis is a measure of the association between two numerical variables.

Question 13

The sum of deviations about the arithmetic mean is always equal to zero.

Question 14

The middle value in an ordered array of numbers is called the mode.

Question 15

Excel can produce individual or multiple descriptive statistics.

Question 16

If the median of a distribution is greater than mean, then the distribution is skewed to the left.

Question 17

Skewness and kurtosis of a data set are measures of the shape of the distribution.

Question 18

If the mean of a distribution is greater than the median, then the distribution is positively skewed.

Question 19

Box and whisker plots $\textbf{ cannot }$ be generated in Excel.

Question 20

The range and interquartile range don't take into account all of the values in a data set when describing variation.

Question 21

The number of standard deviations that a value (x) is above or below the mean is the ___.

A) absolute deviation
B) coefficient of variation
C) interquartile range
D) z score
E) correlation coefficient

Question 22

A commuter travels many kilometres to work each morning. She has timed this trip 5 times during the last month. The time (in minutes) required to make this trip was 34, 39, 41, 35, and 41. The median time (in minutes) required for this trip was ___.

A) 39
B) 41
C) 37.5
D) 38
E) 35.5

Question 23

A commuter travels many kilometres to work each morning. She has timed this trip 5 times during the last month. The time (in minutes) required to make this trip was 34, 39, 41, 35, and 41. The modal time required for this trip was ___.

A) 39
B) 41
C) 37.5
D) 38
E) 35

Question 24

The quartile divides the first three quarters of the data from the last quarter and is equal to the value of the 75th percentile.

A) 1^st
B) 2^nd
C) 3^rd
D) 4^th

Question 25

Consider the following data: 0, 2, 4, 6, 11, 12, 13. The 35^th percentile is

A) 5.
B) 4.
C) 2.
D) 6.
E) 11.

Question 26

The ages of ten seniors are 71, 68, 75, 68, 62, 80, 73, 68, 67, 70. The 90^th percentile is

A) 68.0.
B) 75.5.
C) 70.5.
D) 77.5.
E) 73.0.

Question 27

A statistics student made the following grades on five tests: 84, 78, 88, 72, and 72. What is the median grade?

A) 88
B) 72
C) 78
D) 80
E) 82

Question 28

In a hearing test, subjects estimate the loudness of a sound in decibels. The results are: 71, 68, 75, 68, 62, 80, 73, 68, 68, 67, 70. Compute the median.

A) 68
B) 75
C) 70
D) 69
E) 73

Question 29

___ are quantiles that divide a group of data into 100 parts.

A) Quartiles
B) Quantiles
C) Percentiles
D) Qucentiles

Question 30

An instructor is evaluating the performance of students on a test. He records the number of points that each student missed and created a frequency distribution. This is provided below:
What is the variance for this population?

A) 11.43
B) 135.17
C) 130.67
D) 180.67
E) 198.07

Question 31

A statistics student made the following grades on five tests: 84, 78, 88, 78, and 82. What is the mode?

A) 78
B) 80
C) 88
D) 84
E) 82

Question 32

Quantiles can be used with ___ data only.

A) qualitative
B) quantitative
C) numerical
D) individual points of

Question 33

A statistics student made the following grades on five tests: 84, 78, 88, 78, and 72. What is the mean grade?

A) 78
B) 80
C) 72
D) 84
E) 88

Question 34

The spread or dispersion of a set of data is called

A) range
B) coefficient of variation
C) measures of variation
D) mean absolute deviation

Question 35

___ are used to describe the data set.

A) Quantiles
B) Quartiles
C) Percentiles
D) Qucentiles

Question 36

Liz Chapa manages a portfolio of 250 common stocks. Her staff compiled the following performance statistics for two new stocks: The coefficient of variation for Salas Products, Inc. is ___.

A) 300%
B) 100%
C) 33%
D) 5%
E) 23%

Question 37

A commuter travels many kilometres to work each morning. She has timed this trip 5 times during the last month. The time (in minutes) required to make this trip was 34, 39, 41, 35, and 41. The mean time (in minutes) required for this trip was ___.

A) 35
B) 41
C) 37.5
D) 38
E) 35.5

Question 38

The ages of students in a class have been put into the frequency distribution below.
What is the standard deviation for this (population) set of data?

A) 0.494
B) 0.703
C) 1.12
D) 1.25
E) 1.35

Question 39

Consider the following data: 0, 2, 4, 6, 11, 12, 13. The first (Q1) and third (Q3) quartiles are

A) 0 and 6.
B) 2 and 11.
C) 2 and 12.
D) 0 and 12.
E) 6 and 12.

Question 40

You do $\textbf{ not }$ need to highlight the data in Excel to use it for your analysis.

Question 41

The following frequency distribution was constructed for the age of accounts receivable: The frequency distribution reveals that the accounts receivable ages are ___.

A) skewed to the left
B) skewed to the right
C) not skewed
D) normally distributed
E) symmetrical

Question 42

The following box and whisker plot was constructed for the age of accounts receivable: The box and whisker plot reveals that the accounts receivable ages are ___.

A) skewed to the left
B) skewed to the right
C) not skewed
D) normally distributed
E) symmetrical

Question 43

Excel's most powerful statistical tools are found in the ___ ToolPak.

A) Statistics
B) Descriptive Statistics
C) Analysis
D) Data Analysis

Question 44

Shaun Connor, Human Resources Manager for Oil Terminals (OT), is reviewing the operator training hours at OT nationally. His staff compiled the following table of national statistics on operators training hours. What can Shaun conclude from these statistics?

A) The East Coast distribution is skewed to the left.
B) The East Coast distribution is skewed to the right.
C) The West Coast distribution is skewed to the left.
D) The West Coast distribution is skewed to the right.
E) Both distributions are symmetrical.

Question 45

The number of speeding tickets given by a sample of 14 police officers in a month are as follows: 63, 35, 67, 63, 55, 75, 84, 13, 67, 54, 59, 49, 58, and 67. Compute the range, interquartile range and the standard deviation.

Question 46

The following box and whisker plot was constructed for the age of accounts receivable: The box and whisker plot reveals that the accounts receivable ages are ___.

A) skewed to the left
B) skewed to the right
C) not skewed
D) normally distributed
E) symmetrical

Question 47

When you use Excel's most powerful statistical tools, the results

A) update automatically when you change the data.
B) are static.
C) can only be run for one statistical test at a time.
D) are temporary.

Question 48

The A-Life and Kafi companies have 40 and 65 employees respectively. Their average weekly wages are $450 and $350. The standard deviations are 7 and 9 respectively. Which company has a larger variability in wages?

Question 49

In a hearing test, subjects estimated the loudness of a sound in decibels. The results are: 71, 68, 75, 68, 62, 80, 73, 68, 68, 67, 70. Compute the mean, median and mode.

Question 50

The number of speeding tickets given by a sample of 14 police officers in a month are as follows: 63, 35, 67, 63, 55, 75, 84, 13, 67, 54, 59, 49, 58, and 67. Compute the 5 Number Summary for the sample. (Note: The 5 Number Summary are the minimum, Q1, Q2, Q3 and the maximum).

Question 51

Data values outside the fences in a distribution using a box and whisker plot are ___.

A) inliers
B) outliers
C) boxliers
D) fenceliers

Question 52

The following frequency distribution was constructed for the age of accounts receivable: The frequency distribution reveals that the accounts receivable ages are ___.

A) skewed to the left
B) skewed to the right
C) not skewed
D) normally distributed
E) symmetrical

Question 53

Karen Merlott, VP for Strategic Planning at a recruitment firm, recently conducts a survey to determine customer satisfaction with job placement. She distributed the survey to 45 of the most recently placed executives. Two items on a survey questionnaire them to rate the importance of "initial interview process" and "satisfaction of final job placement" on a scale of 1 to 10 (with 1 meaning " $\textbf{ not }$ important" and 10 meaning "highly important"). Her staff assembled the following statistics on these two items. What can Karen conclude from these statistics?

A) The Initial Interview Process distribution is positively skewed.
B) The Initial Interview Process distribution is not skewed.
C) The Satisfaction of Final Job Placement distribution is negatively skewed.
D) The Satisfaction of Final Job Placement distribution is positively skewed.
E) Both are symmetrically distributed.