STT 215 Exam 1 2025/2026 Exam
Questions with 100% Correct Answers |
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What is statistics? - 🧠 ANSWER ✔✔Collection or gathering of data
Displaying, analyzing, and summarizing data
Inferring information from data
Cases - 🧠 ANSWER ✔✔The objects described by a set of data. May be
customers, companies, subjects in a study, or other subjects
(observations/individuals).
Label - 🧠 ANSWER ✔✔A special variable used in some data sets to
distinguish different cases.
Example: Patient A, Patient B, Patient C, etc.
Variable - 🧠 ANSWER ✔✔A characteristic that varies among individuals in
a population or in a sample (a subset of a population).
Example: age, height, blood pressure, ethnicity, leaf length, first language
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,Distribution - 🧠 ANSWER ✔✔Tells us what values the variable takes and
how often it takes these values.
Categorical variable - 🧠 ANSWER ✔✔Something that falls into one of
several categories. What can be counted is the count or proportion of
individuals in each category.
Example: blood type (A, B, AB, O), hair color, ethnicity
Quantitative (numerical) variable - 🧠 ANSWER ✔✔Something that can be
counted or measured for each individual and then added, subtracted,
averaged, etc. across individuals in the population.
Example: height, age, blood cholesterol level
Quantitative data: discrete versus continous - 🧠 ANSWER ✔✔Discrete if
the possible values are isolated points on the number line.
Continuous if the set of possible values forms an entire interval on the
number line.
Ways to represent categorical data - 🧠 ANSWER ✔✔Frequency / Relative
Frequency distribution
Bar graph
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, Pie chart
Ways to represent numerical data - 🧠 ANSWER ✔✔Frequency distribution
Stemplot (stem-and-leaf plot)
Histogram
Ways to represent bivariate numerical data - 🧠 ANSWER ✔✔Scatter plot
Bar graph - 🧠 ANSWER ✔✔Each category is represented by a bar. The
bar's height shows the count (or sometimes the percentage) for that
particular category.
Pie chart - 🧠 ANSWER ✔✔Peculiarity: the slices mist represent the parts of
one whole (1 or 100%). The size of a slice depends on what percent of the
whole this category represents.
Relative frequency - 🧠 ANSWER ✔✔(frequency) / (number of observations
in the data set)
Stemplot - 🧠 ANSWER ✔✔(Also called a stem-and-leaf plot) Each
observation is represented by a stem, consisting of all digits except the final
one, which is the leaf.
Work best for small numbers of observations that are all greater than 0.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
Questions with 100% Correct Answers |
Latest Update
What is statistics? - 🧠 ANSWER ✔✔Collection or gathering of data
Displaying, analyzing, and summarizing data
Inferring information from data
Cases - 🧠 ANSWER ✔✔The objects described by a set of data. May be
customers, companies, subjects in a study, or other subjects
(observations/individuals).
Label - 🧠 ANSWER ✔✔A special variable used in some data sets to
distinguish different cases.
Example: Patient A, Patient B, Patient C, etc.
Variable - 🧠 ANSWER ✔✔A characteristic that varies among individuals in
a population or in a sample (a subset of a population).
Example: age, height, blood pressure, ethnicity, leaf length, first language
COPYRIGHT@SARAHROSAPERAL 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
1
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,Distribution - 🧠 ANSWER ✔✔Tells us what values the variable takes and
how often it takes these values.
Categorical variable - 🧠 ANSWER ✔✔Something that falls into one of
several categories. What can be counted is the count or proportion of
individuals in each category.
Example: blood type (A, B, AB, O), hair color, ethnicity
Quantitative (numerical) variable - 🧠 ANSWER ✔✔Something that can be
counted or measured for each individual and then added, subtracted,
averaged, etc. across individuals in the population.
Example: height, age, blood cholesterol level
Quantitative data: discrete versus continous - 🧠 ANSWER ✔✔Discrete if
the possible values are isolated points on the number line.
Continuous if the set of possible values forms an entire interval on the
number line.
Ways to represent categorical data - 🧠 ANSWER ✔✔Frequency / Relative
Frequency distribution
Bar graph
COPYRIGHT@SARAHROSAPERAL 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
, Pie chart
Ways to represent numerical data - 🧠 ANSWER ✔✔Frequency distribution
Stemplot (stem-and-leaf plot)
Histogram
Ways to represent bivariate numerical data - 🧠 ANSWER ✔✔Scatter plot
Bar graph - 🧠 ANSWER ✔✔Each category is represented by a bar. The
bar's height shows the count (or sometimes the percentage) for that
particular category.
Pie chart - 🧠 ANSWER ✔✔Peculiarity: the slices mist represent the parts of
one whole (1 or 100%). The size of a slice depends on what percent of the
whole this category represents.
Relative frequency - 🧠 ANSWER ✔✔(frequency) / (number of observations
in the data set)
Stemplot - 🧠 ANSWER ✔✔(Also called a stem-and-leaf plot) Each
observation is represented by a stem, consisting of all digits except the final
one, which is the leaf.
Work best for small numbers of observations that are all greater than 0.
COPYRIGHT@SARAHROSAPERAL 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
3
PRIVACY STATEMENT. ALL RIGHTS RESERVED
