The two ratios we have are:
2/7 is a ratio, and 4/21 is another ratio.
To verify if there is a proportion we need to know if the two ratios are equivalent.
The rule we will follow to verify if they form a proportion is:
if the numerator and denominator of the numerator multiplied by the same number, result in the second ratio, there is a proportion.
The numerator are 2 and 4, so to get the second number from the first one, we have to multiply by 2:
And now we compare the denominators: to go from 7 to a 21, we have to multiply by 3:
Since we don't multiply by the same number, there is not a proportion.
Another way to find the same result is to cross multiply the numbers in the ratios, and if we get the same number, there is a proportion, if not, there is not a proportion:
We check the result is not the same number, thus, there is not a proportion,
Answer: False