Unit Test — Unit test Answers

Two boats depart from a port located at (–10, 0) in a coordinate system measured in kilometers, and they travel in a positive x-direction. The first boat follows a path that can be modeled by a quadratic function with a vertex at (0, 5), and the second boat follows a path that can be modeled by a linear function and passes through the point (10, 4). At what point, besides the common starting location of the port, do the paths of the two boats cross?

The scatterplot shows the distance (in feet) that a person was from a motion sensor during an experiment in math class. Use the labeled points to create a linear model. About what distance in feet (y) would a person be 8 seconds after the experiment begins?

The height of a toy rocket that is shot in the air with an upward velocity of 48 feet per second can be modeled by the function , where t is the time in seconds since the rocket was shot and f(t) is the rocket’s height in feet. What is the maximum height the rocket reaches?

When estimating a job to bid, a contractor’s estimator first determines the actual cost of labor using the functionL(h) = 28.75h, where h is the number of estimated hours it will take to complete the job. Next, the estimator adds the labor burden, which accounts for taxes and insurance, using the function B(L) = 1.78L. Finally, the estimator calculates the selling price, including the markup for overhead and profit, using the function M(B) = 1.43B.

A factory produces 1,250,000 toys each year. The number of toys is expected to increase by about 150% per year. Which model can be used to find the number of toys, n (in millions), being produced in t years?

A company plans to sell pens for $2 each. The company’s financial planner estimates that the cost, y, of manufacturing the pens is a quadratic function with a y-intercept of 120 and a vertex of (250, 370). What is the minimum number of pens the company must sell to make a profit?

Environmentalists estimate an annual population decrease of giraffes in the wild of 3.5% due to development. This can be modeled by the function p(x) = 140,000(0.965)x, where x is the number of years of tracking the populations. Conservationists have developed a sanctuary that has shown the ability to increase the population by 0.85% per year. The increase can be modeled by the function S(p) = p(1.0085)x.

The table shows the population of Center City in various years. Use the data from 1990 and 2005 to create a linear model that predicts the population of the city (y) in a given year (x). In which year was the actual population of Center City most different from the value predicted by this model?YearCity Population1985194,9571990197,8001992199,5322000203,7502005206,5612012210,600

Felix’s Feed Mill sells chicken feed for $8.00 per bag. This price is no longer high enough to create a profit. Felix decides to raise the price. He is considering four different plans.Plan A: Raise the price by $0.10 each week until the price reaches $12.00.Plan B: Raise the price by 10 percent each week until the price reaches $12.00.Plan C: Raise the price by the same amount each week for 8 weeks, so that in the eighth week the price is $12.00.Plan D: Raise the price by $0.25 each week until the price reaches $12.00.Which plan will result in the price of the feed reaching $12.00 fastest?

Which table represents a linear function?

Which characteristic of a data set makes a linear regression model unreasonable?

A rectangular parking lot has a perimeter of 820 ft. The area of the parking lot measures 42,000 ft2. What is a dimension of the parking lot?

A store uses the expression –2p + 50 to model the number of backpacks it sells per day, where the price, p, can be anywhere from $9 to $15. Which price gives the store the maximum amount of revenue, and what is the maximum revenue? (Revenue = price number of backpacks.)

An air show is scheduled for an airport located on a coordinate system measured in miles. The air traffic controllers have closed the airspace, modeled by a quadratic equation, to non-air show traffic. The boundary of the closed airspace starts at the vertex at (10, 6) and passes through the point (12, 7). A commuter jet has filed a flight plan that takes it along a linear path from (–18, 14) to (16, –13). Which system of equations can be used to determine whether the commuter jet’s flight path intersects the closed airspace?

Which scatterplot has a correlation coefficient closest to r = –1?

The function C(L) = |L – 105| can be used to determine the difference between the expected and actual crop of lemons, L, from a single tree. The estimated total weight in pounds of number of lemons can be modeled by the function w(L) = 0.25L.

A modern art piece includes drops of paint spilling periodically into a basin of liquid. The display is timed with an expectation that the circular area of the green spill increases 1.5 square centimeter per hour. Increase in area: A(h) = 1.5h; h in hoursIncrease in diameter: in square centimeters

The graph below represents c, the amount a phone company charges, based on m, the number of minutes the customer uses each month. If there are a maximum of 44,640 minutes in a month, which equation best represents the phone company’s monthly charges?

Graham and Hunter are circus performers. A cable lifts Graham into the air at a constant speed of 1.5 ft/s. When Graham’s arms are 18 ft above the ground, Hunter, who is standing directly underneath Graham, throws Graham a ball as the cable continues to lift him higher. Hunter throws the ball from a position 5 ft above the ground with an initial velocity of 24 ft/s. Which system of equations can be used to model this situation?

Which scatterplot has a correlation coefficient closest to r = 1?