## 1.

## 2.

## 3.

If you chose (A) or (E), you rounded to the nearest hundreds.

If you chose (C), you forgot to round your result.

If you chose (D), you rounded to the correct place, but up instead of down.

## 4.

If you chose (H), you probably found the number of vehicle owners who owned a truck from the years 2000–2009.

If you chose (K), you found the number of vehicle owners surveyed in total.

## 5.

## 6.

## 7.

The mean is the sum of the data set divided by the number of items in the set: . The median is the middle value, which is 22. Therefore, the difference between mean and median is 32.4 — 22 = 10.4.

If you chose (C) or (E), you found either the median or the mean and stopped there.

## 8.

The LCM is 2^{4} x 3 = 48.

If you picked (J), you multiplied all of the numbers together, thereby repeating the shared factors.

(H) and (K) are also multiples of the set of numbers, but not the lowest common multiple possible.

## 9.

## 10.

*x*is odd,

*x*

^{2}=

*x*×

*x*will also be odd, eliminating (J). Since

*x*

^{2}is odd, subtracting 1 will make it an even number.

## 11.

## 12.

## 13.

If you picked any of the other choices, you probably read the graph wrong and found the percentage of students who wrote a different number of minutes to complete the problem.

## 14.

If you chose (J), you probably divided the change in spending, 200 dollars, by the new amount, 400 dollars, instead.

## 15.

If you got (C), you forgot to account for the different probabilities of each roll and calculated the average of 3, 4, 5, 6, and 7.

## 16.

If you got (J), you didn’t notice the repeated letter L.

If you got (K), you calculated the number of rearrangements assuming you could repeat letters.

If you got (F) or (H), you used either the formula for permutations or combinations with *n* = 5 objects and *r* = 2 spaces, without carefully reading the question itself.

## 17.

*x*, the middle value of the set, the median will remain unchanged. However, the mean will increase because the value added above

*x*(the original mean) is significantly larger than the new value added below

*x*. Therefore, the mean is now greater than the median.

## 18.

If you chose (J), you found the probability of either or both of the events occurring—the union instead of the intersection of the two.

## 19.

*x*causes the final expression to have. One where the expression is positive and remains so, and another where it is negative and the absolute value acts as a minus 1 multiplied throughout. Solving both equations will give you the two possible values for

*x*: