Home / 487.38-672.50-312.70

Finding the Fourth Proportional to 487.38, 672.50 and 312.70

Calculator

Solution

The fourth proportional to 487.38, 672.50 and 312.70 is: 431.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.38 : 672.50 = 312.70 : x
  2. Step 2: Convert to fraction form
    487.38/672.50 = 312.70/x
  3. Step 3: Cross multiply
    487.38x = 672.50 × 312.70
  4. Step 4: Simplify right side
    487.38x = 210,290.75
  5. Step 5: Solve for x
    x = 210,290.75/487.38
  6. Step 6: Final answer
    x = 431.47

Related Problems

Find fourth proportional to 243.69, 336.25 and 156.35
Half scale
Find fourth proportional to 974.76, 1,345 and 625.40
Double scale
Find fourth proportional to 488.38, 673.88 and 313.70
Similar ratio
Find fourth proportional to 731.07, 1,008.75 and 469.05
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.