Question

The table shows the values (in thousands) of the average salary of NBA players x years after 1990. Write and use an exponential model to find the year

when the average NBA player's salary will be more than $3 million
1
2
Years, X
3
4
5
0
15
30
Salary, y
60
240
480
120
Write an exponential model for this situation
(put parentheses around the "b" value)
What is the projected salary in 9 years?
In what year would the salary be more than $3 million? (round to two decimal places)

Answer 1

Explanation:

From the given table,

Ratio of each successive term in the row showing salary (y) is,

Ratio =
`(30)/(15)` = 2

Therefore, function representing the relation between average salary (y) and years (x) will be the exponential function.

y = a(b)ˣ

For x = 0, y = 15,

15 = a(b)⁰

a = 15

For x = 1, y = 30,

30 = 15(b)¹

b = 2

Therefore, exponential function Or exponential model will be,

y = 15(2)ˣ

Projected salary in 9 years [For x = 9],

y = 15(2)⁹

y = 15 × 512

y = $7680

For the salary more than $3 million [For y = $3000000],

3000000 = 15(2)ˣ

2ˣ = 200000

log(2)ˣ = log(200000)

xlog2 = log(2×10⁵)

xlog2 = log2 + log(10)⁵

(x - 1)log2 = 5

x - 1 =
`\frac{5}{\text{log2}}`

x = 16.609 + 1

x = 17.609

x ≈ 17.61 years