7. The Calculator Company (TCC) needs to estimate its sales revenue for next year for its most popular line of calculator. The most recent 12 years of revenue data for the company's popular line of calculators is provided below. In addition, the total industry sales revenue for the comparable calculators is also provided.

Year	TCC Sales Revenue (in millions)	Industry Sales Revenue (in billions)	Year	TCC Sales Revenue (in millions)	Industry Sales Revenue (in billions)
1	$46.7	$6.1	7	$101.2	$16.0
2	59.3	11.4	8	100.8	16.0
3	74.2	12.8	9	104.5	16.5
4	77.9	10.5	10	107.1	17.5
5	85.1	15.3	11	109.3	19.5
6	98.0	14.4	12	108.3	18.5

Your work must reflect the correct independent and dependent variables based on the problem statements. This is part of the solution that is required.

a) It is believed that TCC's sales revenue changes with time. Develop a linear regression model that can be used to predict TCC's sales revenue for year 13. Provide the correct independent and dependent variables and provide the linear regression relationship in terms of these independent and dependent variables.What is the forecast for year 13 and based on the strength of the relationship would you use this forecast?