Proportions

Question 1

What is direct proportions?

Answer 1

Direct proportion is when something is equal to another but larger or smaller. It’s a pattern where it can double itself in the perimeter.

Question 2

How do you plot direct proportions?

Answer 2

We can say that Perimeter of a shape is directly proportional to Side lengths. Or we can say that x is directly proportional to y. x ∝y . What’s the relationship? y = 4x

Question 3

How do you find if fractions are in proportion?

Answer 3

Step 1: Write ratios in a/b = c/d format. Step 2: Replace letters with no.s 6/9 = 24/36. Step 3: Check and multiply, 6 x 36 = 216, 9 x 24 = 216.

Question 4

What is the independent and dependant variable mean?

Answer 4

Y is the independent variable and usually is placed in the bottom row.
X is the independent variable and is placed in the top row.
Independent variable doesn’t change but dependent is the thing that changes.

Question 5

How do we know what the rule is and how do we write it?

Answer 5

In the problem figure out the independent and dependent variable label them y and x.

Then state the rule, so y = 5x.

K is the constant.

Question 6

Practice Question:
Sam paid $240(P) for 60 L of fuel at the service station. Find the relationship between P and L. At the same rate how many L would Sam get for $60?

Answer 6

The relationship, step 1:
240 divide 60 = 4, 4 is the relationship between your variables.

240=60k
240=4x60
P=4L

How many litres will Sam get for $60?

60 divide 4=15L

Question 7

A plant nursery used 40kg (M) to plant 200 seedlings (s). Find the 1 between m and s.

How many seedlings could be planted with 50kg of fertiliser?

Answer 7

Finding the relationship between m and s is easy it equals to 5.

But with the second part it’s a trick. It’s not to divide it’s to multiply this is because you are finding the s amount not the m amount.

So the answer is to times 50 by 5 which equals to 250 seedlings.

Question 8

What is the relationship formula for direct proportions and ratios?

Question: Papercity sells 40 packets of paper for $200. How much would it cost for 60 packets?

Answer 8

C=ki
C and I is the constant so the known variables but k is the unknown variable find k.

Answer: 200/40=x/60
X=200x60 divide 40 =300

$300 for 60 paper

Question 9

How do you identify the constant of proportionality graphically (in a graph)?

For example, what line has a constant of proportionality between y and x of 5/4.

Answer 9

Use this formula y/x = K

So you need to find the line that equals to a constant of 1.25.