A statistical program is recommended. The quarterly sales data (number of copies sold) for a college textbook over the past three years follow. Quarter Year 1 Year 2 Year 3 1 1,700 1,810 1,850 2 940 910 1,100 3 2,635 2,900 2,940 4 2,510 2,360 2,625 (a) Construct a time series plot. A time series plot contains a series of 12 points connected by line segments. The horizontal axis is labeled: Year/Quarter. There are 12 tick marks on the horizontal axis which have been divided up into 3 groups of 4 tick marks. The groups are labeled, from left to right: Year 1, Year 2, Year 3. For each year, the individual tick marks are labeled, from left to right: 1, 2, 3, 4. The vertical axis ranges from 0 to 3500 and is labeled: Number of Copies Sold. The points are plotted from left to right in increments of 1 starting at the tick mark labeled 1 in the group Year 1. For each year, the highest point occurs above the tick mark labeled 3, and the lowest occurs above the tick mark labeled 2. When comparing two different points that lie above tick marks of the same number