Question

The function f(x) = 7(1.32)x models the number, in billions, of the DNA sequences in a database x years since 2010. What does the 1.32 represent?

A) The annual increase rate in sequences is 32%.
B) The total increase rate in sequences since 2010 is 32%.
C) The increase rate in sequences before 2010 was 32%.
D) The starting number of sequences in 2010 was 1.32 billion.

Answer 1

The correct option is (A).

Explanation:

The function representing the growth of number, in billions, of the DNA sequences in a database x years since 2010 is:

`f(x)=7\cdot (1.32) x`

The general growth function can be represented as:

`y=a\cdot (1+r)^(t)`

Here,

y = final value

a = initial value

r = growth rate

t = time

Com-paring the two functions we get:

`1+r=1.32\\r=1.32-1\\r=0.32`

This implies that the annual increase rate in number, in billions, of the DNA sequences is 32%.

Thus, the correct option is (A).