Scenario. You run an online business selling cosplay outfits based on popular TV series. This season you have primarily relied on Facebook to advertise your different product lines. For 30 different similarly priced products you have kept records of the amount you spent (in bit cents) on marketing that item versus the quantity sold. In addition to your usual Facebook advertising, you also tried a different approach to marketing one item where you hired an Instagram influencer. This cost 500 bit cents and you sold 263 items. Your task is to develop a linear model that can predict sales based on marketing spend. Subsequently, you want to evaluate if Instagram represents good value for money compared to your usual advertising approach. 1. What is the explanatory variable (x-axis) and what is the response variable (y-axis)? [1 mark] 2. What is the best linear equation for predicting sales based on marketing spend? L.e. what are the intercept and slope terms? [1 mark] 3. What is the correlation between marketing spend and sales? [1 mark] 4. How much of the variation in sales is explained by marketing spend? L.e. what is the coefficient of determination, r2? [1 mark] 5. What is the standard error, se? [1 mark]