PSYC 11 Midterm 1 Review

What is the independent variable (IV), and what is the scale of measurement?

What is the dependent variable (DV)?

• IV: Reality TV show (Nominal)

  DV: Likability (Ordinal)

• IV: Reality TV show (Nominal)

  DV: Likability (Interval)

• IV: Reality TV show (Nominal)

  DV: Likability (Ratio)

• IV: Reality TV show (Ordinal)

  DV: Likability (Interval)

What is the scale of measurement for the variable on the X-axis?

• Nominal

• Ordinal

• Interval

• Ratio

Based on this graph, what would you expect the strength and direction of this relationship?

• Strong, positive

• Weak, positive

• Strong, negative

• Weak, negative

Answer explanation

Values only between -1 and 1

A correlation of r = .93 is very large!

The Pearson r = .93 and indicates a strong, positive correlation.

Write a statement about the relationship between these two variables

Answer explanation

As the number of pets increases, empathy levels also increase

Suppose we were to run a regression on the same data. Identify the a and b coefficients for our regression equation:

Y-hat = a + bx

• a = 7.02 (B17)

  b = 6.64 (B18)

• a = 6.64 (B18)

  b = 7.02 (B17)

• a = .93 (B5)

  b = .86 (B4)

• a = .86 (B4)

  b = .93 (B5)

What is the Least Squares method, and what does tell us?

• Provides us with a line of best fit with the least amount of error between Y and Y-hat

• Provides us with a line of best fit with the most amount of error between Y and Y-hat

• It's totally not important

• It's just a silly little line

Based on the Least Squares method, who has the smallest residual?

• The person with 0 pets

• The person with 1 pet

• The person with 2 pets

• The person with 3 pets

• The person with 4 pets

Interpret the y-intercept by filling in the two blanks.

"When the number of pets owned = (_), then the starting level of empathy is around (_).

• 1) 0

  2) 7.05

• 1) 7.05

  2) 0

• 1) 7.05

  2) 6.63

• 1) 6.63;

  2) 7.05

Interpret the x-intercept by filling in the two blanks.

"For every changed unit in "_", there is a changed amount of (_) in levels of empathy."

• 1) # of pets

  2) 6.63

• 1) # of pets

  2) 7.05

• 1) Levels of empathy

  2) 6.63

• 1) Levels of empathy

  2) 7.05

Y-hat = 7.05 + 6.63(X)

(Solve) How much empathy does one have if they have 7 pets?

Answer explanation