stats review

Question 1

exploratory data analysis (EDA)

Answer 1

first step in data analysis - allows for understanding of structure, quality and patterns

Question 2

numerical data types

Answer 2

continuous: a value within a range
discrete: fixed values, usually counts

Question 3

categorical data types

Answer 3

nominal: unordered categories
ordinal: ordered categories

Question 4

research process

Answer 4

Develop a scientific question.
Collect data.
Analyze data (EDA first, then statistical tests).
Make conclusions based on findings.

Question 5

summarizing numerical data

Answer 5

measures of center: mean, median
measures of spread: range, IQR, standard deviation
five number summary: min, Q1, median, Q3, max

Question 6

summarizing categorical data

Answer 6

summarized using counts and proportions, visualized with bar charts

Question 7

unimodal

Answer 7

one peak

Question 8

multimodal

Answer 8

multiple peaks

Question 9

right skewed

Answer 9

mean > median

Question 10

left skewed

Answer 10

median > mean

Question 11

standard deviation and variance

Answer 11

measures how spread out the data is around the mean, larger standard deviation=wider distribution

Question 12

BRFSS data set

Answer 12

Age distribution: Right-skewed (more younger participants).
Gender: Slightly more females than males.
General health: Most participants reported good to excellent health.
Weight: Some extreme values, but not biologically unrealistic.