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True or False: Statistics is the science of decision making using random selection of choices.
false
A shoe store wants to know how much money
on average
A shoe store wants to know how much money
on average
A shoe store wants to know how much money
on average
True or False: At a birthday party
teams are chosen by putting everyone's name in a hat. Then names are drawn to make up each team.
Is this sampling with replacement?
True or False: At a local seminar
every attendee's name was put into a jar to win a small gift. Names were selected at random
Use the table below about automobiles to classify these columns of data. Which column contains continuous data? -> Weight Which column contains discrete data? -> Number of Seats Which column contains qualitative data? -> Body Style
a) body style b) number of seats c) qualitative data
a) qualitative data b) discrete data c) continuous data
LSU wants to conduct a survey of high school seniors in Louisiana concerning their plans for future education. The survey asks three questions:
Gender - What is the senior's gender? -> GPA - What is the senior's current GPA to two decimal places? Years - How many years it will take the senior to complete high school?
Which variable contains continuous data? -> GPA Which variable contains discrete data? -> Years Which variable contains qualitative data? -> Gender
a) GPA b) Gender c) Years
a) continuous data b) qualitative data c) discrete data
True or False: In a data set used in statistics (imagine a MS Excel spreadsheet)
information for the variables are contained in the columns.
True or False: In a data set used in statistics (imagine a MS Excel spreadsheet)
information about the variables are contained in the columns.
True or False: In a data set used in statistics (imagine a MS Excel spreadsheet)
information about the individuals are contained in the columns.
Randomly choosing several friends to go with you on an automobile trip would be what type of sampling situation?
Random sampling of your friends without replacement.
The Gallup News Service sent out 2
000 questionnaires for survey about climate change. 1
What is the true and final
purpose of statistics?
The average age of students enrolled in last Fall's engineering class was found to be 24 years of age. What type of statistics does this statement describe?
Descriptive statistics.
A confidence interval for the age of students enrolled in last Fall's engineering class was found to be (22
years of age. What type of statistics does this statement describe?
True or False: The distribution of a column of data is given by its shape
location
True or False: In a distribution of a column of data
a statistic for location measures where the middle of the data values lie in a real number line.
In statistics
the mathematical distance between two numbers is defined as
In statistics
the statistical distance between two numbers is defined as
It is known that the science of statistics can determine the relationship between two variables
but that it cannot determine if one variable causes the values in the second variable. What concept makes this statement true?
The first step in doing statistics is always?
Abstract information from the problem.
A distribution of a column of data refers to what three characteristics of the column of data?
The shape
Match the following questions with the correct answer.
a) What characteristic is summarized by the pattern of data values when graphed? b) What characteristic is summarized by the middle of the data values on a real number line? c) What characteristic is summarized by the width of the data values on a real number line?
a) shape b) location c) spread
True or False: The science of statistics summarizes information in a column of data with graphs
numbers
What information is extracted from a column of data by graphs?
General trend of the data values as well as any major exceptions.
True or False: Always look at your data first
before looking at your statistics.
Match the following statistics with the characteristic of a column of data that they summarize.
a) Number of data values. b) Mean or median. c) Standard deviation or inter-quartile range.
a) size b) location c) spread
What one of the following answers is true about a parameter?
A constant that gives population information.
What is the general name for statistics that give information about a column of data?
Descriptive statistics.
What is the general name for statistics that extract the most information from a column of data?
Efficient statistics.
What is the general name for statistics that are less affected by extreme values in a column of data?
Resistant statistics.
Match each characteristic of a distribution with the appropriate statistic for qualitative data.
A. Bar chart. B. Mode. C. Number of categories.
a) shape b) location c) spread
Why is it important to look at the shape of a column of data before interpreting any statistics?
To see if the data is unimodal
Why look at a chart to get shape information instead of looking at the data values themselves?
A chart is needed to summarize the shape characteristic so that we can see it.
Match the two meanings below with their appropriate column titles in a frequency table.
a) Count of the data values in a category. b) Proportion of the data values in a category.
a) frequency b) relative frequency
In the frequency table below
what is the relative frequency for the category Mar? (answer to three decimal places
Which of the following answers is NOT one of the first three columns in a frequency table?
Cumulative Frequency
In the frequency table below
what is the frequency for the category May? (answer to zero decimal places
In the frequency table below
what is the cumulative frequency and the cumulative relative frequency for the category Jun?
What type of graph is most appropriate to use to display the shape of qualitative data?
A bar chart where the bars do not touch each other.
True or False: A Pareto chart just a bar chart with the bars rearranged from the highest bar to the lowest bar.
true
What type of graph is most appropriate to use to display the shape of discrete data?
A histogram where the bars do touch each another.
In a histogram for discrete data
what characteristic is shown on the x-axis
In a histogram for continuous data
what characteristic is shown on the x-axis
True or False: When making a histogram for continuous data
a bin is just a range of possible data values.
True or False: A boxplot is used to display the shape of qualitative data.
false
True or False: A boxplot shows location and spread information as does a histogram.
true
In a boxplot of continuous data
what percent of the data values lie inside the box
In the boxplot below
what is the value of the median?
In any boxplot (an example is shown below)
the width of the box shows what characteristic of the data values?
What is the general approach to analyzing the information in a histogram?
First look at the overall shape
Which of the following answers is NOT one of our overall shapes?
A modeless shape.
True or False: A skewed left shape means that the peak of the histogram is on the left side of the histogram. A skewed right shape means that the peak of the histogram is on the right side of the histogram.
false
Skewness in a histogram is a property of what in the histogram?
The tails.
Which of the following answers is NOT an exception when analyzing a histogram?
Any bimodal shapes.
How is a gap distinguished from an extreme value?
A gap is fits as part of the overall shape. An extreme value is outside the overall shape.
The efficient measure of spread for a column of data is the?
Standard deviation.
True or False: A deviation can never equal zero.
false
A data value close to the mean has a?
Small deviation.
Is the average deviation better than the standard deviation (σ)?
No
What information about a data value is given by its deviation?
The mathematical distance and direction from the mean.
Can the standard deviation (σ) be used to find probability?
Yes
Match the appropriate statistic for a distribution of efficient statistics.
A. Histogram. B. Standard deviation. C. Mean.
a) shape b) spread c) location
What is the statistical term for all the squared deviations added together?
Sum of squares.
What is the formula for the sum of squares (SS)?
sum of squares = E (x- xbar) ^2
To calculate variance
statistics does not average the deviations
What is the appropriate denotation for standard deviation?
σ for population
Which one of the following answers is NOT correct about standard deviation?
squared deviation = variance ^2
Does the sum of squares (SS) usually get bigger as more data values are added to the data set?
Yes
What is the appropriate denotation for variance?
σ2 for population
Two data sets have the same size
but Data set A has a sum of squares of 97 and Data set B has a sum of squares of 197. In which data set are the data values more widely spread out?
Does the average deviation always equal zero for every data set?
Yes
A bigger standard deviation for a data set means the data values are?
Spread wider apart.
Match the appropriate set of statistics to the descriptions below.
a) Extract the most information from a column of data. b) Less affected by extreme values.
a) efficient statistics b) resistant statistics
True or False: The mean (µ) is NOT needed to calculate a deviation.
false
Variance (σ2) is what type of measure of spread?
A measure of spread standardized for the number of data values.
A data value less than the mean has a?
Negative deviation.
The sum of squares (SS) is what type of measure of spread?
A raw measure of spread.
The mean (µ) is used when thinking about the data values in a column of data because? (select two of the answers below)
A single number is easy to think about. The mean best represents the values in the column of data.
How is the sum of squares (SS) standardized into variance (σ2)?
Divide by the degrees of freedom.
True or False: In statistics
a deviation applies to only one data value.
Match the appropriate statistic for a distribution of resistant statistics.
A. Inter-quartile range. B. Boxplot. C. Median.
a) spread b) shape c) location
What are resistant statistics resistant to?
The presence of extreme values.
What makes resistant statistics work?
They look at the position of the data values
To find resistant statistics
what must be true of the data set?
Why do positional statistics work for a data set containing extreme values?
Because in the tails
True or False: Percentiles are NOT positional statistics.
false
When denoting a percentile (Pk) what does the k stand for?
Which percentile is desired
True or False: The value of the third quartile (Ǫ3) can be less than the value of the first quartile (Ǫ1).
false
How many data values are less than the value of the third quartile (Ǫ3)?
Three quarters (75%)of the data values.
True or False: Percentiles (Pk) (or quartiles (Ǫk) must always be a data value in the data set.
false
Which of the answers below are NOT one of the steps to find any percentile (Pk)?
None of the other choices.
True or False: The appropriate equation to use in Step 1: Calculate the Index of finding a percentile (Pk)is shown below.
i = k/ 100 x n
true
In Step 2: Move to the correct position of finding a percentile (Pk)
how is the appropriate move decided?
What is the 40th percentile (P40) in the following ranked set of data (n= 15)? (to one decimal place = 00.0) 9
13
What is the first quartile (Ǫ1) / third quartile (Ǫ3) in the following ranked set of data (n = 15)? (to one decimal place = 00.0) 9
13
What is the 60th percentile (P60) in the following ranked set of data (n = 15)? (to one decimal place = 00.0) 9
13
What is the 90th percentile (P90) in the following ranked set of data (n = 15)? (to one decimal place = 00.0) 9
13
What is sum of the data values less than the 20th percentile (P20) the following ranked set of data (n = 15)? (to one decimal place = 00.0) 9
13
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Flashcard (59)