Home / 20,385.92-28,120.64-12,820.28

Finding the Fourth Proportional to 20,385.92, 28,120.64 and 12,820.28

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Solution

The fourth proportional to 20,385.92, 28,120.64 and 12,820.28 is: 17,684.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,385.92 : 28,120.64 = 12,820.28 : x
  2. Step 2: Convert to fraction form
    20,385.92/28,120.64 = 12,820.28/x
  3. Step 3: Cross multiply
    20,385.92x = 28,120.64 × 12,820.28
  4. Step 4: Simplify right side
    20,385.92x = 360,514,478.58
  5. Step 5: Solve for x
    x = 360,514,478.58/20,385.92
  6. Step 6: Final answer
    x = 17,684.48

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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.