Home / 128,981.34-178,011.12-72,392.72

Finding the Fourth Proportional to 128,981.34, 178,011.12 and 72,392.72

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Solution

The fourth proportional to 128,981.34, 178,011.12 and 72,392.72 is: 99,911.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    128,981.34 : 178,011.12 = 72,392.72 : x
  2. Step 2: Convert to fraction form
    128,981.34/178,011.12 = 72,392.72/x
  3. Step 3: Cross multiply
    128,981.34x = 178,011.12 × 72,392.72
  4. Step 4: Simplify right side
    128,981.34x = 12,886,708,276.99
  5. Step 5: Solve for x
    x = 12,886,708,276.99/128,981.34
  6. Step 6: Final answer
    x = 99,911.42

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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.