A population, P(t) (in millions) in year t, increases exponentially. Suppose P(9)=16 and P(18)=24. a) Find a formula for the population in the form P(t)=abt. Enter the values you found for a and b in your formula in the blanks below. Round your values to 4 decimal places.

Respuesta :

Answer:[tex]\frac{32}{3}\left ( 1.0460\right )^t[/tex]

Step-by-step explanation:

Given

Population changes exponentially

[tex]P\left ( t\right )=ab^t[/tex]

[tex]P\left ( 9\right )=16[/tex]------1

[tex]P\left ( 9\right )=16=ab^8[/tex]

[tex]P\left ( 18\right =24=ab^{18}[/tex]-----2

divide 1 & 2 we get

[tex]\frac{24}{16}=\frac{b^{18}}{b^9}[/tex]

[tex]\frac{3}{2}=b^9 [/tex]

Substitute [tex]b^9[/tex] in 1 we get

[tex]a=\frac{32}{3}[/tex]

Thus [tex]P\left ( t\right )=\frac{32}{3}\left ( 1.0460\right )^t[/tex]

Answer:

[tex]P(t)=10.6667(1.0461)^t[/tex]

[tex]a\approx 10.6667[/tex]

[tex]b\approx 1.0461[/tex]

Step-by-step explanation:

It is given that a population, P(t) (in millions) in year t, increases exponentially.

The given values of he function are P(9)=16 and P(18)=24.

The formula for the population in the form

[tex]P(t)=ab^t[/tex]

where, a is the initial population and b is growth factor.

P(9)=16 means P(t)=16 at x=9.

[tex]16=ab^9[/tex]          .... (1)

P(18)=24 means P(t)=24 at x=18.

[tex]24=ab^{18}[/tex]          .... (2)

Divide equation (2) by equation (1).

[tex]\dfrac{24}{16}=\dfrac{ab^{18}}{ab^9}[/tex]

[tex]1.5=b^9[/tex]

[tex](1.5)^{\frac{1}{9}}=b[/tex]

[tex]b\approx 1.0461[/tex]

Substitute [tex]b^9=1.5[/tex] in equation (1).

[tex]16=a(1.5)[/tex]

Divide both sides by 1.5.

[tex]\dfrac{16}{1.5}=a[/tex]

[tex]a\approx 10.6667[/tex]

Substitute the values of a and b in the given formula.

[tex]P(t)=10.6667(1.0461)^t[/tex]

Therefore, the formula for population is [tex]P(t)=10.6667(1.0461)^t[/tex].