STAT 201 - FINAL EXAM VERIFIED ACCURATE STUDY
GUIDE
Design - Answers - Stating questions of interest and plan to get a sample.
Description - Answers - Summarizing and Analyzing data obtained.
Inference - Answers - Conclusions made for the entire population.
Population - Answers - The group of all or every item. "All USC students" or "Every
resident of SC".
Sample - Answers - A subset of the population. "A sample of 100 USC students" or "A
sample of 500 residents of SC."
Parameter - Answers - Results from a population. (remember both begin with the letter
p). "The % of all USC students" or "The average number of pets for every resident of
SC".
Statistic - Answers - Results from a sample. (remember both begin with the letter s).
"The % of a sample of USC students" or "The average number pets for a sample of
residents of SC"
Descriptive Statistics - Answers - Methods for summarizing collected data.
Inferential Statistics - Answers - Decisions/predictions about a population.
Sampling Methods - Answers - o Require some element of randomization.
o Sampling is required most of the time because to study the entire population would
take too long, cost too much, and be much harder to work with.
Discrete Quantitative Variables - Answers - Variables where the data represents counts.
Look for keyphrase "the number of ..."
Continuous Quantitative Variables - Answers - - Variables where the data represents
measurements. - Think of numbers that have units on them. - Measurements are things
like money, weight, length, time, etc.
Categorical Variables - Answers - - Variables where the data represents categories -
Anything that is not quantitative is categorical. - Anything that is not a number is
categorical but there are some numbers that are categorical (any number that does not
represent a count or a measurement; such as, zip code or social security number).
, Graphs for Categorical Variables - Answers - Bar Chart, Pie Chart, and Pareto Chart (a
bar chart with categories arranged in descending order by count).
Graphs for Quantitative Variables - Answers - Stem-and-Leaf Display, histogram
(similar to bar chart but bars are touching and axis is a number line), and dot plot. (all of
these graphs have some sort of number line.)
Mean - Answers - Average and acts as the balance point.
Median - Answers - Middle value in an ordered array. 50% of data is less than it and
50% of data is more than it.
Mode - Answers - Most common value in the dataset.
Range - Answers - Total spread in the data. Difference between the maximum and the
minimum.
Standard Deviation - Answers - Typical (or average) difference between the
observations and the mean.
Z-score - Answers - The number of standard deviations from the mean a particular
observation falls. The difference between a value and the mean in terms of the number
of standard deviations
First Quartile - Answers - 25th percentile. 25% of the data is below the number and 75%
of the data is above the number.
Second Quartile - Answers - Median
Third Quartile - Answers - 75th percentile. 75% of the data is below the number and
25% of the data is above the number.
Five Number Summary - Answers - Minimum, first quartile, second quartile, third
quartile, and maximum.
Interquartile Range - Answers - The range of the middle 50% of the data. The difference
between the third and first quartile.
Non-resistant measurements (affected by outlier) - Answers - Mean, range, standard
deviation, minimum, and maximum.
Resistant measurements (not affected by outlier) - Answers - Median, mode, the
quartiles, and interquartile range.
A value is unusual (an outlier) if... - Answers - the z-score is more than three standard
deviations from the mean; in other words, if z < -3 or z > 3.
GUIDE
Design - Answers - Stating questions of interest and plan to get a sample.
Description - Answers - Summarizing and Analyzing data obtained.
Inference - Answers - Conclusions made for the entire population.
Population - Answers - The group of all or every item. "All USC students" or "Every
resident of SC".
Sample - Answers - A subset of the population. "A sample of 100 USC students" or "A
sample of 500 residents of SC."
Parameter - Answers - Results from a population. (remember both begin with the letter
p). "The % of all USC students" or "The average number of pets for every resident of
SC".
Statistic - Answers - Results from a sample. (remember both begin with the letter s).
"The % of a sample of USC students" or "The average number pets for a sample of
residents of SC"
Descriptive Statistics - Answers - Methods for summarizing collected data.
Inferential Statistics - Answers - Decisions/predictions about a population.
Sampling Methods - Answers - o Require some element of randomization.
o Sampling is required most of the time because to study the entire population would
take too long, cost too much, and be much harder to work with.
Discrete Quantitative Variables - Answers - Variables where the data represents counts.
Look for keyphrase "the number of ..."
Continuous Quantitative Variables - Answers - - Variables where the data represents
measurements. - Think of numbers that have units on them. - Measurements are things
like money, weight, length, time, etc.
Categorical Variables - Answers - - Variables where the data represents categories -
Anything that is not quantitative is categorical. - Anything that is not a number is
categorical but there are some numbers that are categorical (any number that does not
represent a count or a measurement; such as, zip code or social security number).
, Graphs for Categorical Variables - Answers - Bar Chart, Pie Chart, and Pareto Chart (a
bar chart with categories arranged in descending order by count).
Graphs for Quantitative Variables - Answers - Stem-and-Leaf Display, histogram
(similar to bar chart but bars are touching and axis is a number line), and dot plot. (all of
these graphs have some sort of number line.)
Mean - Answers - Average and acts as the balance point.
Median - Answers - Middle value in an ordered array. 50% of data is less than it and
50% of data is more than it.
Mode - Answers - Most common value in the dataset.
Range - Answers - Total spread in the data. Difference between the maximum and the
minimum.
Standard Deviation - Answers - Typical (or average) difference between the
observations and the mean.
Z-score - Answers - The number of standard deviations from the mean a particular
observation falls. The difference between a value and the mean in terms of the number
of standard deviations
First Quartile - Answers - 25th percentile. 25% of the data is below the number and 75%
of the data is above the number.
Second Quartile - Answers - Median
Third Quartile - Answers - 75th percentile. 75% of the data is below the number and
25% of the data is above the number.
Five Number Summary - Answers - Minimum, first quartile, second quartile, third
quartile, and maximum.
Interquartile Range - Answers - The range of the middle 50% of the data. The difference
between the third and first quartile.
Non-resistant measurements (affected by outlier) - Answers - Mean, range, standard
deviation, minimum, and maximum.
Resistant measurements (not affected by outlier) - Answers - Median, mode, the
quartiles, and interquartile range.
A value is unusual (an outlier) if... - Answers - the z-score is more than three standard
deviations from the mean; in other words, if z < -3 or z > 3.
