Final answer:
To solve the proportion 3/12 = 1/x, you cross multiply to get 3x = 12. Dividing both sides by 3 then gives x = 4, so the complete equation is 3/12 = 1/4.
Step-by-step explanation:
To find the missing number in the division equation 3/12 = 1/x, you need to set up the equation as a proportion. The goal is to find the value of x that makes the two ratios equal. For this particular question, the equation can be solved by cross multiplication.
First, we set up the proportion: 3/12 = 1/x. To solve for x, cross multiply to get 3 × x = 12 × 1. This simplifies to 3x = 12.
To isolate x, divide both sides of the equation by 3. The calculation will look like this: x = 12 / 3. So, the missing number x is 4. Therefore, the equation 3/12 = 1/4 is the correct proportion.
To find the missing number in the equation 3/12 = 1/? using division, we can set up a proportion. We know that the numerator of the first fraction (3) is divided by the denominator of the first fraction (12), which gives us the result of the second fraction (1). So, we can write the proportion as 3/12 = 1/x. To solve for x, we can cross multiply and solve the resulting equation: 3x = 12 * 1. Dividing both sides by 3, we find that x = 4. Therefore, the missing number is 4.