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Finding the Fourth Proportional to 920.08, 1,378.68 and 487.12

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Solution

The fourth proportional to 920.08, 1,378.68 and 487.12 is: 729.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.08 : 1,378.68 = 487.12 : x
  2. Step 2: Convert to fraction form
    920.08/1,378.68 = 487.12/x
  3. Step 3: Cross multiply
    920.08x = 1,378.68 × 487.12
  4. Step 4: Simplify right side
    920.08x = 671,582.60
  5. Step 5: Solve for x
    x = 671,582.60/920.08
  6. Step 6: Final answer
    x = 729.92

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.