PLEASE HELP ME


Which kind of function best models the data in the table? Use differences or ratios.


X | Y

0 | 0.6

1 | 4.2

2 | 29.4

3 | 205.8

4 | 1440.6


A. Linear

B. Quadratic

C. Exponential

D. None or the above

Respuesta :

Answer:

C. Exponential

Step-by-step explanation:

If the function is linear, the differences will be equal.

d₁ = y₁ βˆ’ yβ‚€ = 4.2 βˆ’ 0.6 = 3.6

dβ‚‚ = yβ‚‚ βˆ’ y₁ = 29.4 βˆ’ 4.2 = 25.2

d₃ = y₃ βˆ’ yβ‚‚ = 205.8 βˆ’ 29.4 = 176.4

dβ‚„ = yβ‚„ βˆ’ y₃ = 1440.6 βˆ’ 205.8 = 1234.8

The differences are not equal, so this is not linear.

If the function is quadratic, the differences of the differences will be equal.

dβ‚‚ βˆ’ d₁ = 25.2 βˆ’ 3.6 = 21.6

d₃ βˆ’ dβ‚‚ = 176.4 βˆ’ 25.2 = 151.2

dβ‚„ βˆ’ d₃ = 1234.8 βˆ’ 176.4 = 1058.4

The differences of the differences are not equal, so this is not quadratic.

If the function is exponential, the ratios will be equal.

r₁ = y₁ / yβ‚€ = 4.2 / 0.6 = 7

rβ‚‚ = yβ‚‚ / y₁ = 29.4 / 4.2 = 7

r₃ = y₃ / yβ‚‚ = 205.8 / 29.4 = 7

rβ‚„ = yβ‚„ / y₃ = 1440.6 / 205.8 = 7

The ratios are equal, so the function is exponential.