Question

@skullpatrol

Answer 1

The number of subscribers y to a magazine after t years is shown by the equation below:

y = 95(0.75)t

Which conclusion is correct about the number of subscribers to the magazine?

It increased by 25% every year.
It decreased by 25% every year.
It increased by 75% every year.
It decreased by 75% every year.

Answer 2

i bleive this one is d

Answer 3

Is t an exponent?

Answer 4

yes t is an expontnet @mathstudent55

Answer 5

ok @skullpatrol jstu to clarify d is wrong?

Answer 6

based on what you are showing me it is increasing

Answer 7

yes

Answer 8

$$\Huge y = 95(0.75)^t$$

Answer 9

is that^ the equation?

Answer 10

https://www.google.ca/search?q=y+%3D+95(0.75)t&oq=y+%3D+95(0.75)t&aqs=chrome..69i57j69i64&sourceid=chrome&es_sm=122&ie=UTF-8#q=y+%3D+95(0.75)%5Et

Answer 11

yes @skullpatrol

Answer 12

Calculate the function for t = 0.

\(y = 95(0.75)^0 = 95 \times 1 = 95\)

At t = 0, the initial numbers of subscribers is 95.

Now let's calculate y for t = 1, at the end of 1 year.

\(y = 95(0.75)^1 = 95 \times 0.75 = 71.25\)

At t = 1, the end of the first year, the number of subscribers is 71.25.

Now calculate the percent decrease from 95 to 71.25:

\(percent~change = \dfrac{71.25 - 95}{95} \times 100 = -25\%\)

A negative percent change is a decrease. The decrease is 25% per year.

Answer 13

This problem can be solved without graphs or any calculations.
All you need to do is to compare the equation you were given with the growth/decay formula:

\(F = P(1 + r)^t\)

where F = future amount,
P = present amount
r = rate of increase or decrease
t = time in years

If r is a rate of increase, then r is positive. A negative r means a rate of decrease.

Now let's compare this formula with your given equation.

\(y = 95(0.75)^t\) must fit into

\(F = P(1 + r)^t\), then you get

\(y = 95[1 + (-0.25)]^t\)

Notice that to have 1 + r in the parentheses, you need to write 0.75 as
1 + (-0.25). This clearly shows that the rate is 25% decrease annually.

Answer 14

thank you