A ratio shows the relative size of parts of a group.Baking, science, and any time you want to compare or exchange amounts of something use ratios.Two ratios are in proportion.You will need to determine whether or not the two ratios are in proportion when you are presented with them.If you can make true statements about their values, you should be able to solve the problem.You can find the missing value of a ratio using simple math.
Step 1: The denominator of each ratio should be identified.
The colon, the word "to", and the fraction bar can be used to express ratios.Put your ratios as fractions.The number below the bar is the denominator.If the ratio of cats to dogs in one shelter is 6 to 4, and another shelter has 39 to 26 cats, you would rewrite the ratios as 64displaystyle frac64.The denominators are 4 and 26.
Step 2: For the two denominators, find the least common multiple.
The smallest multiple each denominator has in common is the least common multiple.The ratios cannot be in proportion if there is no least common multiple.Both the denominators 4 and 26 are multiples of 52.
Step 3: The equivalent fraction should be written for the first ratio.
Divide the least common multiple by the denominator to find the equivalent fraction.This quotient is the numerator.The new numerator will be your equivalent fraction.If the first ratio is 64, you would divide the least common multiple by 4.
Step 4: The second ratio is equivalent to the equivalent fraction.
The same steps were used to find the equivalent fraction for the first ratio.If the second ratio is 3926, you would divide the least common multiple by 26:52.
Step 5: The two fractions should be compared.
The two original ratios are in proportion if the two fractions are equal.For example, 7852 is a displaystyle of frac7852.
Step 6: The ratios should be equivalent fractions.
A colon (1:2displaystyle 1:2) or the word "to" can be used to express ratios.Turn your ratios into fractions if you set them this way.If you are comparing the ratios 6 to 4 and 39 to 26, set them up as follows.
Step 7: The first fraction and the second fraction have the same numerator and denominator.
This product should be placed to the right of the equation.For example, 626 is a displaystyle of 6 times 26.
Step 8: The numerator of the second fraction should be the same as the first fraction.
This product should be placed to the left of the equation.For example, 439 is a displaystyle with 39 times.
Step 9: The two products should be compared.
The ratios are in proportion if they are the same.You know that 64926=3displaystyle frac64 is related to 156.
Step 10: The ratios should be set as fractions.
The colon and the word "to" are used to express ratios.Turn your ratios into fractions if you set them this way.If you want to figure out how many cups of flour you need to make 20 batches of cookies, you can use a variable.The first ratio is 64.Since you are trying to find out how many cups of flour you need to make 20 batches of cookies, the second ratio is x 20.The proportion will be set up like this.
Step 11: Multiply the numerator of the first fraction by the second fraction.
The product should be placed to the right of the equation.For example, 620 is a display style with 20 times.
Step 12: The numerator of the second fraction is the same as the first fraction.
This product should be placed to the left of the equation.For example, 4x=4xdisplaystyle 4 times x 4x64
Step 13: Find the answer for xdisplaystyle.
The missing number is in your second ratio.The two ratios are not the same.If you need 6 you can use this example.64 and 3020 displaystyles are ratios in proportion.