HW 10 Practice

The error term e is a random variable in regression analysis. What is the mean (or expected value) of e?

0

Consider the estimated regression equation:

y_hat = b₀ + b₁x

Which of the following is a correct statement?

b₁ is the slope

What is the measure that quantifies the proportion of variation in the dependent variable y explained by the estimated regression equation?

The coefficient of determination.

A mobile app analytics team examines how the number of influencer posts affects app downloads. A regression analysis leads to the following equation for predicting downloads (in thousands) from the number of influencer posts:

y_hat = 30,000 + 9x

What can we determine from this equation?

Each individual influencer post is associated with an

_________

of

_________

in app downloads.

an average increase; 9000

What variable is being predicted in regression analysis?

The dependent variable.

When the correlation between two variables is very weak, how does this affect the coeffcient of determination?

The coefficient of determination will…

be close to or equal to 0.

If the correlation coefficient is negative, what can be inferred about the regression line or related values?

The slope of the regression line must be negative.