Respond to the following in a minimum of 175 words: on 3 different documents
Models help us describe and summarize relationships between variables. Understanding how process variables relate to each other helps businesses predict and improve performance. For example, a marketing manager might be interested in modeling the relationship between advertisement expenditures and sales revenues.
Consider the dataset below and respond to the questions that follow:
Advertisement ($’000)   Sales ($’000)
1068    4489
1026    5611
767      3290
885      4113
1156    4883
1146    5425
892      4414
938      5506
769      3346
677      3673
1184    6542
1009    5088

  • Construct a scatter plot with this data.
  • Do you observe a relationship between both variables?
  • Use Excel to fit a linear regression line to the data. What is the fitted regression model? (Hint: You can follow the steps outlined on page 497 of the textbook.)
  • What is the slope? What does the slope tell us?Is the slope significant?
  • What is the intercept? Is it meaningful?
  • What is the value of the regression coefficient,r? What is the value of the coefficient of determination, r^2? What does r^2 tell us?
  • Use the model to predict sales and the business spends $950,000 in advertisement. Does the model underestimate or overestimates ales?