Question

A population of beetles is growing according to a linear growth model. Initially, there were 20 beetles, and 6 weeks later, there were 25 beetles.(a) Write a linear model to describe the number of beetles over time, using weeks as the unit of time.Pt= (b) How many beetles are there expected to be 17 weeks after the initial point? beetles(c) When do you expect the number of beetles to reach 85? Round your answer to the nearest week.After weeks

Answer 1

a) P(t) = 5/6t + 20

b) 34.2 beetles

c) After 78 weeks.

Step-by-step explanation:

a) A general linear growth model can be expressed as P(t) = at + b, where P is the number of beetles in time t and t is the time in weeks.

It is known that:

P(0) = 20

P(6) = 25

These values can be substituted in the general equation to find a and b:

P(t) = at + b

P(0) = 20:

20 = a*0 + b

20 = 0 + b

20 = b

So,

P(t) = at + 20

Using P(6) = 25:

25 = a*6 + 20

25 - 20 = a*6

5 = a*6

5/6 = a

So, the linear growth model can the represented as:

P(t) = 5/6t + 20

b)

The number of beetles after 17 weeks is P(17):

P(17) = 5/6*17 + 20

P(17) = 14.1 + 20

P(17) = 34.2

34.2 beetles.

c)

P(t) = 85

85 = 5/6t + 20

85 - 20 = 5/6t

65 = 5/6t

t = 65*6/5

t = 78

After 78 weeks.