Home / 721-995.79-487.72

Finding the Fourth Proportional to 721, 995.79 and 487.72

Calculator

Solution

The fourth proportional to 721, 995.79 and 487.72 is: 673.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    721 : 995.79 = 487.72 : x
  2. Step 2: Convert to fraction form
    721/995.79 = 487.72/x
  3. Step 3: Cross multiply
    721x = 995.79 × 487.72
  4. Step 4: Simplify right side
    721x = 485,666.70
  5. Step 5: Solve for x
    x = 485,666.70/721
  6. Step 6: Final answer
    x = 673.60

Related Problems

Find fourth proportional to 360.50, 497.90 and 243.86
Half scale
Find fourth proportional to 1,442, 1,991.58 and 975.44
Double scale
Find fourth proportional to 722, 997.17 and 488.72
Similar ratio
Find fourth proportional to 1,081.50, 1,493.69 and 731.58
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.