# MATHEMATICS

Top of Form 1. Stream quality is based on the levels of many variables, including the following. Which of these variables is quantitative?

The amount of dissolved oxygen

The number of distinct species present

The amount of phosphorus

All of the above

2. Which of the following is a discrete variable?

Weight of a fish

Length of a fish

None of the above

Number of toxins present in a fish

3. During winter, red foxes hunt small rodents by jumping into thick snow cover. Researchers report that a hunting trip lasts on average 19 minutes and involves on average 7 jumps. They also report that, surprisingly, 79% of all successful jumps are made in the northeast direction. Three variables are mentioned in this report. The first variable mentioned is

ordinal.

quantitative and discrete.

quantitative and continuous.

categorical.

4. A sample of 55 streams in severe distress was obtained during 2007. The following is a bar graph of the number of streams that are from the Northeast, Northwest, Southeast, or Southwest. In the bar graph, the bar for the Northeast has been omitted.

The number of streams from the Northeast is

35.

25.

15.

45.

5. Here is a stemplot (with split stems) of body temperatures (in degrees Fahrenheit) for 65 healthy adult women.

The first quartile for this data set is

97.6.

97.5.

98.0.

97.9.

6. Researchers measured the length of the central retrix (R1), a flight-involved tail feather, in 21 female long-tailed finches. Here is a boxplot of the length, in millimeters (mm).

Based on this boxplot, which of the following statements is TRUE?

The distribution of R1 lengths is bimodal.

The distribution of R1 lengths is mildly right-skewed with a high outlier.

75% of the birds in this study had an R1 length above 70 mm.

All of the above

7. Geckos are lizards with specialized toe pads that enable them to easily climb all sorts of surfaces. A research team examined the adhesive properties of 7 Tokay geckos. Below are their toe-pad areas (in square centimeters, cm2). 5.6

4.9

6.0

5.1

5.5

5.1

7.5

To be an outlier, an observation must fall outside the range 4.9 to 7.5. 4.2 to 6.9. 3.75 to 7.35. 5.1 to 6.0. 8. The median age of five people on a committee is 30 years. One of the members, whose age is 50 years, resigns. The median age of the remaining four people in the committee is not able to be determined from the information given. 25 years. 30 years. 40 years. 9. By inspection, determine which of the following sets of numbers has the smallest standard deviation. 7, 8, 9, 10 0, 0, 10, 10 0, 1, 2, 3 5, 5, 5, 5 10. The volume of oxygen consumed (in liters per minute) while a person is at rest and while he or she is exercising (running on a treadmill) was measured for each of 50 subjects. The goal is to determine if the volume of oxygen consumed during aerobic exercise can be estimated from the amount consumed at rest. The results are plotted below. The scatterplot suggests that there is a positive association between the volume of oxygen consumed at rest and while running. there is an outlier in the plot. both 1 and 2 are true. neither 1 nor 2 is true.