According to the producer price index database maintained by the Bureau of Labor Statistics, the average cost of computer equipment fell 3.6 percent between January and December 2018.

Required:

1. Conduct a horizontal analysis by calculating the year-over-year changes in each line item, expressed in dollars and in percentages, for the income statement of Computer Tycoon Incorporated for the year ended December 31, 2018.

2-a. Conduct a vertical analysis by expressing each line as a percentage of total revenues.

2-b. Excluding income tax, interest, and operating expenses, did Computer Tycoon earn more gross profit per dollar of sales in 2018 compared to 2017?