Question Explanations For
Practice Test 4 (Math Calculator)
This means that x = 3 or x = -2. Plugging these values of x into either equation shows you that the two solutions are (3, 20) and (–2, –10). This gives two possible values of xy: 60 and 20. Since only 60 is an answer choice, (D) is correct.
(A) and (B) are incorrect because the means are the same. (C) is incorrect because Data Set A has a larger standard deviation that Data Set (B), not smaller.
(A) is incorrect because sharing goals showed a greater increase in physical activity than participation on a sports team. (C) is incorrect because the control group did not decrease in physical activity over time. (D) is incorrect because although it may be true, this conclusion is not related to the data presented in the graph.
Using process of elimination, you can see that (A) is incorrect because although there were fewer establishments in 2007 than in 2002, the value of shipments increased. (C) is incorrect because although there were fewer employees in 2007 than in 2002, the average pay increased. (D) is incorrect because although there were fewer establishments in 2007 than in 2002, there were more people employed.
Using process of elimination, (A) is incorrect because the chart only presents some of the data collected, and does not incorporate other modes of transportation (subways, for example). You can confirm this by showing that no more than 7% of people combined walked or biked to work, so the other 93% of people must use other transportation.
(B) is incorrect because although the percentage of commuters who biked to work stayed about the same, the data does not show the number of commuters.
(C) is incorrect because by looking at the slope of each line segment, you can see that the percentage of commuters who walked to work actually decreased more slowly between 1990 and 2000 than between 1980 and 1990.