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Finding the Fourth Proportional to 817.22, 1,225.20 and 509

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Solution

The fourth proportional to 817.22, 1,225.20 and 509 is: 763.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.22 : 1,225.20 = 509 : x
  2. Step 2: Convert to fraction form
    817.22/1,225.20 = 509/x
  3. Step 3: Cross multiply
    817.22x = 1,225.20 × 509
  4. Step 4: Simplify right side
    817.22x = 623,626.80
  5. Step 5: Solve for x
    x = 623,626.80/817.22
  6. Step 6: Final answer
    x = 763.11

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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.