CBA #9 Review - Part 1 Exponential

Scientists are studying a bacteria sample. The function f(x) = 245(1.12)^x gives the number of bacteria in the sample at the end of x days. Which statement is the best interpretation of one of the values in this function?

• The initial number of bacteria is 12.

• The initial number of bacteria decreases at a rate of 88% each day.

• The number of bacteria increases at a rate of 12% each day.

• The number of bacteria at the end of one day is 245.

A student used f(x) = 5.00(1.012)^x to show how the balance in a savings account will increase over time. What does the 5.00 represent?

• The interest the savings account earned for the first year

• The annual interest rate of the savings account

• The number of years the savings account has earned interest

• The starting balance of the savings account

The starting annual salary for an office worker at a company is $29,000. If the company awards an annual increase of 6.2%, which graph models this situation after the office worker receives x annual increases?

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The number of stores opened by a coffee company can be modeled by the exponential function graphed on the grid, where x is the number of years since 1992.

Based on the graph, which statement does not appear to be true?

• The coffee company had opened 400 stores by the end of 1992.

• The coffee company opened 100 stores in one year.

• Every year the number of stores the coffee company opened increased by 25%.

• Since 1992 the coffee company has opened 250 stores each year.

The graph of an exponential function is shown on the grid. Which dashed line is an asymptote for the graph?

• Line q

• Line r

• Line s

• Line t

Which statement about the graph of y = 8(0.25)^x is true?

• The coordinates of the x-intercept are (0.25, 0).

• The coordinates of the y-intercept are (0, 8).

• The equation of the asymptote is x = 0.

• The graph includes the point (2, 1).

The amount of fertilizer in a landscaping company's warehouse decreases at a rate of 3% per week. The amount of fertilizer in the warehouse was originally 78,000 cubic yards. Which function models the amount of fertilizer in cubic yards left after w weeks?

• f(w) = 0.97(78,000)^w

• f(w) = 1.03(78,000)^w

• f(w) = 78,000(0.97)^w

• f(w) = 78,000(1.03)^w

The table contains some points on the graph of an exponential function. Based on the table, which function represents the same relationship?

• q(x) = (0.25)^x

• q(x) = 256(0.25)^x

• q(x) = 0.0625(4)^x

• q(x) = 0.5(4)^x

The graph shows the number of game consoles sold in millions since 2009. Based on this information, which function best models the number of game consoles sold in millions x years since 2009?

• g(x) = 0.6(25.5)^x

• g(x) = 25.5(0.6)^x

• g(x) = 6.12(25.5)^x

• g(x) = 25.5(6.12)^x

A particular type of cell doubles in number every hour. Which function can be used to find the number of cells present at the end of h hours if there are initially 4 of these cells?

• n = 4 (1/2)^h

• n = 4 (2)^h

• n = 4 + (2)^h

• n = 4 + (1/2)^h