Home / 487-672.12-280

Finding the Fourth Proportional to 487, 672.12 and 280

Calculator

Solution

The fourth proportional to 487, 672.12 and 280 is: 386.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    487 : 672.12 = 280 : x
  2. Step 2: Convert to fraction form
    487/672.12 = 280/x
  3. Step 3: Cross multiply
    487x = 672.12 × 280
  4. Step 4: Simplify right side
    487x = 188,193.60
  5. Step 5: Solve for x
    x = 188,193.60/487
  6. Step 6: Final answer
    x = 386.43

Related Problems

Find fourth proportional to 243.50, 336.06 and 140
Half scale
Find fourth proportional to 974, 1,344.24 and 560
Double scale
Find fourth proportional to 488, 673.50 and 281
Similar ratio
Find fourth proportional to 730.50, 1,008.18 and 420
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.