Exam 9: Modeling Our World

Draw a graph of the function and use the graph to answer the question. -The cost of tuition at one community college is $400 plus $125 per credit. Graph the equation, and find the cost if a student registers for 12 credits.

Write a short statement that expresses a possible function between the given variables. -(price of a DVD player, demand for DVD player)

Draw a graph of the function and use the graph to answer the question. -During the month of January, the depth of the snow, at the base of one ski resort, decreased by 2 inches each day. On December 31st there was a base of 64 inches. Graph the equation and use the Graph to estimate the depth of snow on January 28th.

The given table represents a function. Make a clear graph of the function. Date Average High Temperature Jan. 1 4 Feb. 1 3 Mar. 1 4 Apr. 1 5 May 1 6 June 1 7 July 1 8 Aug. 1 8 Sep. 1 8 Oct. 1 7 Nov. 1 5 Dec. 1 4 Dec. 31 4

Write an equation for the linear function and use it to answer the given question. -Normaltown High School's pool record for the 100-yard freestyle was 47.8 in 1990. Assume that the record falls at a constant rate of 0.03 second per year. What does the model predict for the Record in 2010?

There are currently 67 million cars in a certain country, decreasing by 0.5% annually. How many years will it take for this country to have 38 million cars? Round to the nearest year.

Plot and label the given points. - $(-4,-6),(-6,6)$

Write an equation for the linear function and use it to answer the given question. -The price of a particular model car is $10,171 today and rises with time at a constant rate of $1146 per year. How much will a new car cost in 4.1 years?

Write an equation for the linear function and use it to answer the given question. -You can rent time on computers at the local copy center for a $7 setup charge and an additional $4 for every 5 minutes. How much time can you rent for $16?

What is comprised of the values of the dependent variable?

Write an equation for the linear function and use it to answer the given question. -In the town of Oak Forest, a 2% local sales tax and a 9% state sales tax are charged on all retail sales. Let p be the before-tax amount of a purchase in dollars. Let T be the after-tax amount of the Purchase. Find a linear equation that describes how T varies with p. What is the total price of an Item that costs $50 before taxes?

In the following situation, state whether two variables are related in a way that might be described by a function. If so, identify the independent and dependent variables. -You make a list of the titles of books in a public library and their copyright year.

Provide an appropriate response. -Between 1998 and 2002, the average rate of inflation for a particular country was about 5% per year. If a cart of groceries cost $109 in 1998, what did it cost in 2002?

Plot and label the given points. -The rate of change is equal to the slope of the graph.

Create the required linear function an use it to answer the question. -In 1995 the United States recovered 25% of its municipal wastes through recycling, up from 17% in 1990. Let P represent the percentage recycled and t the number of years since 1990. Based on these Two data points, create a linear equation for the function that describes how P varies as a function of Time. Use this function to predict the percentage recycled in 2006.

Plot and label the given points. - $(1,5),(3,-5)$

Find the slope of the graph and they y -intercept. Then sketch the graph for values of x between -10 and 10. - $y = - 2 x + 1$

Solve the equation for the unknown quantity x. - $3 ^ { x } = 27$

Create the required linear function an use it to answer the question. -Persons taking a 30-hour review course to prepare for a standardized exam average a score of 620 on that exam. Persons taking a 70-hour review course average a score of 798. Based on these two Data points, create a linear equation for the function that describes how score varies as a function of Time.

Solve the equation for the unknown quantity x. - $8 ^ { x / 5 } = 55$