Official Explanation
1. The value of n is greater than 0.2 for_____________points on the graph.
According to the graph, the value n represents the ratio of the number of sales made to the number of cold calls made. Since the number of sales is represented in hundreds, per 1000 calls, and the number of calls is represented in thousands, then you will have to be mindful of these increments when expressing n as a ratio. For example, if a point on the graph rests at (3,3), then this represents 300 sales per 1000 calls for 3000 total calls, or 900 sales for 3000 calls, and n would thus have a value of \(\frac{900}{3000}=0.3\). With this calculation, ten of the twelve points on the graph have a value for n that is larger than 0.2:
Point n value
(1, 2)
200 sales per 1000 calls for 1000 total calls = 200 sales for 1000 calls. n=200/1000=0.2
(1, 2.9)
290 sales per 1000 calls for 1000 total calls = 290 sales for 1000 calls. 290/1000=0.29
(1, 4.2)
420 sales per 1000 calls for 1000 total calls = 420 sales for 1000 calls. 420/1000=0.42
Answer: D
2. For sales per 1000 calls, the difference between the highest value shown for 2003 and the lowest value shown for 2005 represents approximately___________from the 2003 value.
This question asks you to calculate the difference between the highest value shown for sales per thousand calls in 2003 and the lowest value shown for sales per thousand calls in 2005, and then to determine what percent change that would be from the 2003 value. The highest value shown for 2003 is a little bit above 3, or 3.1, and the lowest value shown for 2005 is 2. Therefore, the 2005 value is a decrease from the 2003 value. First, you should try to ballpark that difference. The change from 3 to 2 is 1 so the percent decrease is roughly one third, or 33%. However, there are two values close to 33%, so you'll have to do the calculation. To figure the percent decrease, calculate \(\frac{difference}{original amount}\) or \(\frac{3.1-2}{3.1}=\frac{1.1}{3.1}=.5848\)
Therefore, the percent decrease is approximately 35%.
Answer: B