Could anybody help me to solve these problems? Thank you.

Problem 1 The manager of the purchasing department of a large company would like to develop a regression model to predict the average amount of time it takes to process a given number of invoices. Data are collected on the number of invoices processed and the total time taken (in hours). The scatterplot below includes 30 observations and three potential models (Line A, Line B, and Line C). 4.0 Line A: 3.5 Line B: Line C: 3.0 2.5 Processing Time 2.0 1 5 50 100 150 200 250 Number of Invoices (a) Are these 30 observations the population or the sample? Briefly explain. (b) Among Line A, B, and C, which one has the smallest RSS and why? Briefly explain. (c) Among Line A, B, and C, which one has the smallest slope? Which one has the smallest intercept? Briefly explain. (d) If we use Line C as the fitted model, which of the following would be true? Please select the best answer. Briefly explain. A: All of the residuals are negative. B: All of the errors are negative