If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Integrated math 3

### Course: Integrated math 3>Unit 9

Lesson 4: Modeling with two variables

# Graph labels and scales

When graphing a real-world relationship, we need to pick labels and axis scales that are appropriate for the purpose of our model. Created by Sal Khan.

## Want to join the conversation?

• to me i see no way you could use it like this in everyday life except, possibly your job • I have another problem that I can't figure out. It goes like this:
Ashley is doing some math exercises on a website called Khan Academy. In Khan Academy, you have to get at least 70% of the problems in an exercise right in order to gain proficiency.
So far, Ashley has answered correctly 3 out of 7 times. Suppose she answers all of the following q questions correctly and gains proficiency in the exercise.
Write an inequality in terms of q that models the situation.

None of it makes sense to me. How are you supposed to do this problem? • Let q = questions answered correctly

Key Terms:
- At least get 70%
- Assume Ashley solves all of the questions correctly after answering 3

"at least 70% of the problems in an exercise right"
Translated: .7 <= [expression]

"So far, Ashley has answered correctly 3 out of 7 times." and "Suppose she answers all of the following q questions correctly and gains proficiency in the exercise."
Ashley already got 3/7 correct ! Excellent, and now she solved q questions correctly.

Imagine this:
[correct questions]/[total questions]
Correct questions would be 3+q
Total questions would be 7+q, because we don't know how many questions she answered ! We just know that she answered q questions correctly after getting 3 questions correct.

Our inequality now is:

.7 <= (3+q)/(7+q)
hopefully that helps !
• How did Chloe model her graph as P=20-25*(0.8)^t? How did she derive (0.8)^t? And why didn't she derive P= 0-25 degrees instead of 20-25? I'm just curious how to use these parameters sometime for my own experiment.

(1 vote) • Unfortunately, this is just a model non-representative with real life for the sake of explaining exponential models. However though in exponential equations:
a(b)^x+c

a = Initial Value
b = Constant trend growth/decay
x = Time (determined by how you define it
c = Horizontal Asymptote (as you increase x, the output will level out to this value