Home / 498.35-687.71-288.39

Finding the Fourth Proportional to 498.35, 687.71 and 288.39

Calculator

Solution

The fourth proportional to 498.35, 687.71 and 288.39 is: 397.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.35 : 687.71 = 288.39 : x
  2. Step 2: Convert to fraction form
    498.35/687.71 = 288.39/x
  3. Step 3: Cross multiply
    498.35x = 687.71 × 288.39
  4. Step 4: Simplify right side
    498.35x = 198,327.24
  5. Step 5: Solve for x
    x = 198,327.24/498.35
  6. Step 6: Final answer
    x = 397.97

Related Problems

Find fourth proportional to 249.17, 343.85 and 144.20
Half scale
Find fourth proportional to 996.69, 1,375.41 and 576.78
Double scale
Find fourth proportional to 499.35, 689.08 and 289.39
Similar ratio
Find fourth proportional to 747.52, 1,031.56 and 432.59
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.