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Finding the Fourth Proportional to 775.11, 1,069.12 and 479.87

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Solution

The fourth proportional to 775.11, 1,069.12 and 479.87 is: 661.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.11 : 1,069.12 = 479.87 : x
  2. Step 2: Convert to fraction form
    775.11/1,069.12 = 479.87/x
  3. Step 3: Cross multiply
    775.11x = 1,069.12 × 479.87
  4. Step 4: Simplify right side
    775.11x = 513,038.61
  5. Step 5: Solve for x
    x = 513,038.61/775.11
  6. Step 6: Final answer
    x = 661.89

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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.