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Finding the Fourth Proportional to 782.20, 1,170.78 and 416.08

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Solution

The fourth proportional to 782.20, 1,170.78 and 416.08 is: 622.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.20 : 1,170.78 = 416.08 : x
  2. Step 2: Convert to fraction form
    782.20/1,170.78 = 416.08/x
  3. Step 3: Cross multiply
    782.20x = 1,170.78 × 416.08
  4. Step 4: Simplify right side
    782.20x = 487,138.14
  5. Step 5: Solve for x
    x = 487,138.14/782.20
  6. Step 6: Final answer
    x = 622.78

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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.