Direct variation is a relation that has the form
y = kx
where k is the constant of proportionality.
If you are told that a relation is a direct proportion, and you are given one data point, you can find k. The you can write the equation of the direct relation.
Here is an example.
The price of gasoline follows a direct variation.
John bought 5 gallons of gas and paid $15.
a) Write an equation for the relation.
b) Using the relation you found, how much do 13.8 gallons cost?
Solution:
Since the relation is a direct variation, it follows the general equation of a direct variation:
y = kx
We are given one data point, 5 gallons cost $15.
We plug in 5 for x and 15 for y and we find k.
y = kx
15 = k * 5
k = 3
Now that we know that k = 3, we rewrite the relation using our value of k.
y = 3x
This is the answer to part a).
Part b)
We use our relation, y = 3x, and we plug in 13.8 into x and find y.
y = 3x
y = 3 * 13.8
y = 41.4
The price of 15 gallons of gas is $41.40.
The answer is D: 10-19, 20-29, 30-39, 40-49: Frequency 3, 2, 6, 3.
Simply put, The frequency of a particular data value is the number of times the data value occurs. A frequency table is constructed by arranging collected data values in ascending order of magnitude with their corresponding frequencies. I hope this helps with answering any further questions. Good luck!
Answer:
600 calories
Step-by-step explanation:
120 (# of minutes in 2 hours) divided by 40 is 3, so multiply 200 by 3 and you get 600
