On naomi's cell phone plan, the amount she pays each month for international text messages is proportional to the number of international texts she sends that month. last month, she paid $7.20 for 24 international texts.
a. what is the constant of proportionality in this proportional relationship?
b. write an equation to represent this proportional relationship. make sure to define the variables you use.

A) The constant of proportionality in this proportional relationship is

B) The equation to represent this proportional relationship is y = 0.3x

Solution:

Given that, the amount she pays each month for international text messages is proportional to the number of international texts she sends that month

Therefore,

This is a direct variation proportion

Let "y" be the amount that Naomi pays each month

Let "x" be the number of international texts she sends that month

Therefore,

y = kx -------- eqn 1

Where, "k" is the constant of proportionality

Thus the constant of proportionality in this proportional relationship is:

Last month, she paid $7.20 for 24 international texts.

Therefore,

y = $ 7.20

x = 24

Thus from eqn 1,

Substitute k = 0.3 in eqn 1

y = 0.3x

Thus the equation to represent this proportional relationship is y = 0.3x

you never say the total so we cant find the percentage used for petrol

step-by-step explanation:

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6