Stats test

Explain in one or two sentences which variable is the explanatory variable, and which is the response variable in this linear regression model.

The explanatory variable is the pH level as this is the variable used to predict the response variable in mercury level.

The response variable is the average mercury level as this is the outcome being predicted and the variables whose value depends on the pH level.

The sample correlation for this association is r = -0.84. Interpret the correlation in one or two sentences.

The correlation r=-0.84 represents a strong negative linear relationship between pH level and average mercury level, as pH level increases, average mercury level decreases.
The value indicates a negative association as fairly strong and consistent across the lakes sampled.

Interpret the y-intercept of the regression model in context and explain if it is meaningful in this context. Explain your answer in one or two sentences.

When the pH level equals zero, the mercury level for lake water is predicted to be (insert y- intercept and units).

It is not meaningful as its not realistic for lake water to have a pH of 0 - value may require extraploation.

OR

This is meaningful, it is possible for a country to have no change in unemployment rate.

Interpret the slope of the regression model in context. Explain your answer in one or two sentences.

When the pH leavel for lake water increases by 1, the average mercury level for lake water is predicted to decrease by (insert slope and units).