question

A study is conducted to measure children's growth rates without any treatment applied to the children. What best classifies this study?
Choose the correct answer below.
Discrete data
Experiment
Simple random sample
Observational study

answer

Observational study

question

Which of the following is typically the least important factor to consider when conducting a statistical analysis of data?
Choose the correct answer below.
Sampling method
Source of the data
Context of the data
Formula calculation

answer

Formula calculation

question

Fill in the blank.
_______ is used when subjects are assigned to different groups through a process of random selection.

answer

Randomization

question

Which of the following corresponds to the case when every sample of size n has the same chance of being chosen?
Choose the correct answer below.
Simple random sample
Experiment
Probability sample
Random sample

answer

simple random

question

Which of the following is NOT a voluntary response sample?
Choose the correct answer below.
Quiz scores from a college level statistics course are analyzed to determine student progress.
A survey is taken at a mall by asking passersby if they will fill out the survey.
A radio station asks for call-in responses to a question concerning city recycling.
A local dentist asks her patients to fill out a questionnaire and mail it back to determine the quality of the care received during an office visit.

answer

Quiz scores from a college level statistics course are analyzed to determine student progress.

question

Which of the following would be classified as categorical data?
Choose the correct answer below.
Hair color
Your answer is correct.
Number of suitcases on a plane
Amount of rainfall
Tree height

answer

Hair color

question

Which level of measurement consists of categories only where data cannot be arranged in an ordering scheme?
Choose the correct answer below.
Interval
Ordinal
Nominal
Your answer is correct.
Ratio

answer

nominal

question

Which of the following is associated with a parameter?
Choose the correct answer below.
Data that were obtained from a sample.
Data that were obtained from an entire population.
Data that were obtained from a voluntary poll at the end of a service call.
A numerical measurement describing some characteristic of a sample.

answer

Data that were obtained from an entire population.

question

What is the goal of learning statistics?
Choose the correct answer below.
To accept the source of the data blindly
To use statistics for deception
To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed
To use voluntary response samples to imply results about the population

answer

To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed

question

Which of the following is NOT a level of measurement?
Choose the correct answer below.
Quantitative
Your answer is correct.
Ratio
Ordinal
Nominal

answer

Quantitative

question

Which sampling method divides the population up into sections, randomly selects some of those sections, then chooses all the members from the selected sections to study?
Choose the correct answer below.
Convenience
Cluster
Stratified
Systematic

answer

Cluster

question

What does it mean for the findings of a statistical analysis of data to be statistically significant?
Choose the correct answer below.
The likelihood of getting these results by chance is very small.
The results are very important to the health and well-being of a certain population.
The outcome could easily occur by chance.
The results do not make enough difference to be of use.

answer

The likelihood of getting these results by chance is very small.

question

Which of the following consists of discrete data?
Choose the correct answer below.
Amount of rainfall
Number of suitcases on a plane
Tree height
Hair color

answer

Number of suitcases on a plane

question

Fill in the blank.
If we are collecting sample data for a study, the _______ that we choose can greatly influence the validity of our conclusions. For example, we can use sound statistical methods to analyze data in voluntary response samples, but the results are not necessarily valid.

answer

sampling method

question

Survey questions may be misleading if they are "loaded." To what does "loaded" refer?
Choose the correct answer below.
Not concise; very long drawn out questions
Too much data
Questions that trigger a nonresponse
Intentionally worded to elicit a desired response

answer

Intentionally worded to elicit a desired response

question

Which of the following is NOT a misuse of statistics?
Choose the correct answer below.
Utilizing valid statistical methods and correct sampling techniques
Misleading graphs
Making conclusions about a population based on a voluntary response sample
Concluding that a variable causes another variable because they have some correlation

answer

Utilizing valid statistical methods and correct sampling techniques

question

Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each subdivision?
Choose the correct answer below.
Convenience
Systematic
Cluster
Stratified

answer

stratified

question

Which of the following would be considered practically significant?
Choose the correct answer below.
8 out of 14 births resulted in male children.
An average of 1.2 pounds was lost over a 12 month period using a new diet program.
1 out of 50 people were not smoking 12 months after completing a non-smoking program.
In a very large study, it was found that Treatment I resulted in 93% success while Treatment II resulted in 75% success.

answer

In a very large study, it was found that Treatment I resulted in 93% success while Treatment II resulted in 75% success.

question

Which of the following would NOT cast doubt of the usefulness of sample data?
Choose the correct answer below.
Nonresponse
An effective sampling method
Order of questions in a survey
Missing data

answer

An effective sampling method

question

A _______ histogram has the same shape and horizontal scale as a histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.

answer

relative frequency

question

A _______ helps us understand the nature of the distribution of a data set.

answer

frequency distribution

question

In a _______ distribution, the frequency of a class is replaced with a proportion or percent.

answer

relative frequency

question

The bars in a histogram _______.

answer

touch

question

A histogram aids in analyzing the _______ of the data.

answer

shape of the distribution

question

Class width is found by _______.
Choose the correct answer below.
subtracting the lower limit of one class from the upper limit of that same class
subtracting a lower class limit from the next consecutive lower class limit
subtracting the smallest value in the data set from the largest value in the data set
adding the lower class limit to the upper class limit and dividing by two

answer

subtracting a lower class limit from the next consecutive lower class limit

question

_______ are sample values that lie very far away from the majority of the other sample values.

answer

outliers

question

Which characteristic of data is a measure of the amount that the data values vary?
Choose the correct answer below.
Center
Time
Distribution
Variation

answer

variation

question

A(n) _______ distribution has a "bell" shape.

answer

normal

question

The heights of the bars of a histogram correspond to _______ values.

answer

frequency

question

When drawings of objects are used to depict data, false impressions can be made. These drawings are called _______.

answer

pictographs

question

In a graph, if one or both axes begin at some value other than zero, the differences are exaggerated. This bad graphing method is known as _______.

answer

a nonzero axis

question

A _______ is a plot of paired data (x,y) and is helpful in determining whether there is a relationship between the two variables.

answer

scatterplot

question

Which of the following is a common distortion that occurs in graphs?
Choose the correct answer below.
Labeling both axes
Using points above the class midpoints at the heights of the class frequencies
Using bars to represent the frequency of data values
Using a two-dimensional object to represent data that are one-dimensional in nature

answer

Using a two-dimensional object to represent data that are one-dimensional in nature

question

Fill in the blank.
A(n) _______ uses line segments to connect points located directly above class midpoint values.

answer

frequency polygon

question

Which of the following is NOT true about statistical graphs?
Choose the correct answer below.
They utilize areas or volumes for data that are one-dimensional in nature.
Similar graphs can be constructed in order to compare data sets.
They can be used to consider the overall shape of the distribution.
They can be used to identify extreme data values.

answer

They utilize areas or volumes for data that are one-dimensional in nature.

question

Why is it important to learn about bad graphs?
Choose the correct answer below.
So that we can critically analyze a graph to determine whether it is misleading
So that we can represent data the way we would like it to look
To learn how to draw pictographs
To learn how to create frequency distributions

answer

So that we can critically analyze a graph to determine whether it is misleading

question

A _______ is a graph of each data value plotted as a point.

answer

dotplot

question

We utilize statistical _______ to look for features that reveal some useful or interesting characteristics of the data set.

answer

graphs

question

For data sets having a distribution that is approximately bell-shaped, _______ states that about 68% of all data values fall within one standard deviation from the mean.

answer

the Empirical Rule

question

The Range Rule of Thumb roughly estimates the standard deviation of a data set as _______.

answer

s= range/4

question

Which of the following is NOT a value in the 5-number summary?
Choose the correct answer below.
Median
Minimum
Mean
Q1

answer

mean

question

When a data value is converted to a standardized scale representing the number of standard deviations the data value lies from the mean, we call the new value a _______.

answer

z-score

question

Which of the following is NOT a property of the standard deviation?
The units of the standard deviation are the same as the units of the original data.
The standard deviation is a measure of variation of all data values from the mean.
When comparing variation in samples with very different means, it is good practice to compare the two sample standard deviations.
The value of the standard deviation is never negative.

answer

When comparing variation in samples with very different means, it is good practice to compare the two sample standard deviations.

question

Fill in the blank.
In modified boxplots, a data value is a(n) _______ if it is above Q3plus+(1.5)(IQR) or below Q1minus−(1.5)(IQR).

answer

outlier

question

The square of the standard deviation is called the _______.

answer

variance

question

Which of the following is NOT a measure of center?
Choose the correct answer below.
census
median
mode
mean

answer

census

question

Which measure of variation is very sensitive to extreme values?
Choose the correct answer below.
Mean
Histogram
Median
Range

answer

range

question

Methods used that summarize or describe characteristics of data are called _______ statistics.

answer

descriptive

question

Which of the following is NOT a characteristic of the mean?
Choose the correct answer below.
The mean takes every data value into account.
The mean is called the average by statisticians.
The mean is relatively reliable.
The mean is sensitive to outliers.

answer

The mean is called the average by statisticians.

question

The measure of center that is the value that occurs with the greatest frequency is the _______.

answer

mode

question

A value at the center or middle of a data set is a(n) _______.

answer

measure of center

question

A data value is considered _______ if its z-score is less than minus−2 or greater than 2.

answer

significantly low or significantly high

question

Which of the following is always true?
Choose the correct answer below.
Data skewed to the right have a longer left tail than right tail.
The mean and median should be used to identify the shape of the distribution.
In a symmetric and bell-shaped distribution, the mean, median, and mode are the same.
For skewed data, the mode is farther out in the longer tail than the median.

answer

In a symmetric and bell-shaped distribution, the mean, median, and mode are the same.

question

Whenever a data value is less than the mean, _______.

answer

the corresponding z-score is negative