Question

Someone please help!!
MEDAL?(:

Answer 1

In an experiment, a petri dish with a colony of bacteria is exposed to cold temperatures and then warmed again.

Time (hours) 0 1 2 3 4 5 6
Population (1000s) 5.1 3.03 1.72 1.17 1.38 2.35 4.08

Answer 2

a. Find a quadratic model for the data in the table.

Answer 3

b. Use the model to estimate the population of bacteria at 9 hours.

Answer 4

@zepdrix

Answer 5

Look at the attachment below to view how the data was entered.

Check out the quadratic regression online calculator at:
http://www.had2know.com/academics/quadratic-regression-calculator.html

@ErinWeeks

Answer 6

@ErinWeeks
u can set up 3 system of equations to solve for ur A, B, and C in ur quadratic equation becuz a quadtratic equation is in the form Ax^2+Bx+c=y
so...u can have
\[5.1=a(0^{2})+b(0)+c\]

Answer 7

\[1.72=a(2^{2})+b(2)+c\]

Answer 8

\[1.17=a(3^{2})+b(3)+c\]

Answer 9

and all u ahve to do is solve for a and b

Answer 10

now why am I just solving for those specific calculations?

Answer 11

actually, u dont have to, i just picked those. u can pick any other 3 if u want to

Answer 12

It doesnt matter which ones I have to solve for or is it like I can choose any of those calculations and for one of them I just have to solve for A & B?

Answer 13

no, u need all three of those to solve. its call a system of equations. this is what u do to solve for more than 1 varibale. when i said choose any 3. i meant any pairs of ur x and y from ur data

Answer 14

u have ur basic quadratic equation right?

\[a ^{2}+bx+c=y\]

Answer 15

ok we can use those three if itll be enough to get my question right... what do we start off with

Answer 16

with the first equation, after simplifying, u should see that c=5.1. ok?

Answer 17

ok how did I get it to C=5.1

Answer 18

see, my first equation. this si what u get after simplifying