Unit 2

Question 1

Is _____ a categorical/qualitative Variable?
1. Educational attainment
2. Age groups

Answer 1

1. Yes. Different levels of education are categories, not numerical measures.
2. Yes. Age group is more of a category, not an individual number.

Question 2

Mosaic Graph

Question 3

r (correlation coefficient)

Answer 3

Strength and direction of correlation

Question 4

r² (coefficient of determination)

Answer 4

Measures how well the dependent variable(Y-Axis) explains the independent variable(X-Axis)
An r value closer to 1 means the model does a great job explaining the data

Question 5

Limit Grouping

Answer 5

Method used to organize continuous quantitative data using ranges(Class Intervals). The lower class limit is the lowest value, and the upper class limit is the highest value in the class.

Question 6

Limit Grouping: width of classes

Answer 6

(Range) / (number of classes)
**round for neatness (EX: round 7 to 10)

Question 7

Limit grouping: class lower/upper limit

Answer 7

Lower limit: Smallest value or a number below the min value
Upper limit: Largest value or a number above the max value

Question 8

Slope of Regression

Answer 8

b: Slope of regression line
r: Correlation coefficient
sₓ, sᵧ: Standard deviations of x and y
b = r × (sᵧ / sₓ)

Question 9

Y-intercept(a)

Answer 9

a: Y-intercept of regression line
ȳ: mean of y variable
x̄: mean of x variable
a = ȳ − bx̄

Question 10

Regression Line

Answer 10

ŷ: Predicted value
a: Y-intercept of regression line
b: Slope of regression line
ŷ = ax + b

Question 11

Residual

Answer 11

Residual = y − ŷ