Question

Kim is studying the sale of a particular brand of cereals from the year 2000 to 2010. She writes the following function to model the sale of the cereal S(t), in million dollars, after t years:

S(t) = t2 + 7t + 69

Part A: What does the y-intercept of the graph of the function represent? (4 points)

Part B: What is the reasonable domain of the graph of the function? (3 points)

Part C: What is the average rate of change of the sale of the cereal from the first year to the fourth year? Show your work. (3 points)
I JUST NEED PART C!!!!! PLEASEEEEEE JUST PART C IF ANYBODY CAN HELP ME

Answer 1

@campbell_st

Answer 2

average rate of change will be the slope from the points of year 1 and year 4,

so, lets calculate what the sale is for year 1, what do you get?

Answer 3

@DemolisionWolf 2000

Answer 4

@DemolisionWolf is it 2000

Answer 5

S(t) = t2 + 7t + 69

let t = 1
= 1^2 + 7(1) + 69
= 77

so, we have a point of (1, 77)

now u try with year 4
so, t=4

Answer 6

@DemolisionWolf so for year 1 it is 4 years. Can you help me with the year 2??

Answer 7

so the total sales for year 1, was $77
to find the total sales for year 4, we need to plug in 4 every where we see 't' in the equation:
t^2 + 7t + 69

and solve

Answer 8

@DemolisionWolf So when i do 4*4 and get my answer that will be the answer for year 4??

Answer 9

@DemolisionWolf Can you stil help me??

Answer 10

umm i'm not sure i understand why you want to do 4*4?

to get the answer for year 4, just do
t=4
t^2 + 7t + 69

and solve

Answer 11

@DemolisionWolf How do I do that!!!!!

Answer 12

@DemolisionWolf I got 76.

Answer 13

t^2 + 7t + 69
4^2 + 7(4) + 69
16 + 28 + 69