#### 题目列表

During a sales contest at a local electronics store, 65 employees sold a total of $91,000 worth of merchandise. If the standard deviation of sales among those employees was$130 and the sales were normally distributed, what percentage of employees sold \$1270 or more worth of merchandise?
On the most recent test in stats class, Jamal scored x points and Raya scored 73 points. If the average of Cliff and Rayas scores is 79 points, and the average of Jamal and Cliffs scores is 89, then x =_____
After preparing the results of their measurement of the weight of children that participated in their pediatric study, Stephs graduate assistant spilled coffee on their papers. If Steph is able to read that 50 lbs is the third standard deviation to the left of the mean, and 110 lbs also falls on a standard deviation, then which of the following could be the mean weight of the children in the study, assuming regular distribution?Indicate all possible values.
Jeff and Ali race each other at the Tentleytown Speedway. Alis car travels at 300 feet per second, and Jeffs car travels at 250 feet per second. If one lap around the track is 3000 feet long, and each car travels at a constant rate, how many laps will it take Ali to overtake Jeff?
Helen and Sergey must cut down a row of trees. Helen can cut down the entire row in 3 hours, and Sergey can cut down the entire row in 7 hours. If they simultaneously start cutting trees, each starting at one end of the row and working towards each other, what fraction of the trees will Sergey have cut at the time they meet?_____
In a set of five consecutive integers, which of the following must change the average of the set without changing its original median ?
Paul is able to grade p essays every half hour, and Sarah is able to grade s essays every hour. If Paul and Sarah work together grading essays for h hours, then in terms of p, s, and h, how many essays will they grade?Indicate all such amounts.
If the average of 5 numbers is 36 and the average of four of those numbers is 34, then what is the value of the fifth number?
Noahs contracting company builds road at a rate of 1 mile per week, except during the rainy season, when that rate drops to $\frac{1}{2}$ mile per week. If Noah is hired to build 11 miles of road, and his company begins construction 5 weeks before the start of the rainy season, how many weeks will it take Noah`s company to complete the contract? (Rainy season lasts 14 weeks.)_____
Two cyclists, A and B, are 145 miles apart on a straight road. At 1:30 p.m., cyclist A begins riding at a constant speed of 20 miles per hour toward cyclist B. At 2:00 p.m., cyclist B begins riding toward cyclist A at a constant speed. At 5:00 p.m. they meet. How fast, in miles per hour, was cyclist B riding?_____
Portia rates all her first dates as either "duds" or "dudes." Her date on Wednesday night was a dud. On the next night, she went on a date with someone else who was also a dud. If the probability of her getting two duds in a row was $\frac{4}{25}$, what is the probability that her next date will be a dude ?
Victor is walking at a rate of 1 mile every 17 minutes. Sarah is walking at a rate of 1 mile every 14 minutes. If they are 10 miles apart and are approaching each other along a straight road, how many hours will it take them to meet, rounded to the nearest hundredth?_____

(3p+1)(3p-1)

#### Quantity B

$9p^{2}$

a > 0

(a + 2)(3a + 6)

(3a + 2)(a + 6)

#### Quantity A

$3^{2}-2^{2}$

#### Quantity B

$(3-2)(3+2)$

If $(2x+2)^2=0$, then x =_____
a > 0

#### Quantity A

(–a – 10)(10 + a)

#### Quantity B

10

(y – 1)(y + 5) = 0

y

#### Quantity B

3

If m > 0 and $3m^2$ + 12m – 15 = 0, then m =_____
If the difference between two numbers is 4, then which of the following would be sufficient to determine the value of each of the numbers?Indicate all possible values.

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