Question time-y
| Time (years) | Total amount (dollars) |
|---|---|
Sara opened a savings account at a bank. The table shows the exponential relationship between the time , in years, since Sara opened the account and the total amount , in dollars, in the account. If Sara made no additional deposits or withdrawals, which of the following equations best represents the relationship between and ?
Time (years) Total amount (dollars) 0 670.00 1 674.02 2 678.06 Sara opened a savings account
Hard-difficulty · SAT Math · Nonlinear Functions — Exponential growth and decay functions. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.
Answer explanation
Choice B is correct. It’s given that the relationship between and is exponential. The table shows that the value of increases as the value of increases. Therefore, the relationship between and can be represented by an increasing exponential equation of the form , where and are positive constants. The table shows that when , . Substituting for and for in the equation yields , which is equivalent to , or . Substituting for in the equation yields . The table also shows that when , . Substituting for and for in the equation yields , or . Dividing both sides of this equation by yields . Subtracting from both sides of this equation yields . Substituting for in the equation yields . Therefore, of the choices, choice B best represents the relationship between and .
Choice A is incorrect and may result from conceptual or calculation errors.
Choice C is incorrect and may result from conceptual or calculation errors.
Choice D is incorrect and may result from conceptual or calculation errors.
More Nonlinear Functions practice questions
- f x = 4 x 2 - 50 x + 126 The given equation
- The function p is defined by p n = 7 n 3 . What
- The parabola opens downward. The vertex is at point (4 comma 9). The parabola
- f x = x + 7 2 + 4 The function f is defined
- The function f w = 6 w 2 gives the area of a rectangle,
- The exponential function g is defined by g x = 19 · a x
- In quadrant 3, the curve rises to its maximum at point (0 comma negative
- q ( x ) = 32 ( 2 x ) Which table gives three
Browse all Passport to Advanced Math practice questions or return to the full SAT question bank.
