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Finding the Fourth Proportional to 812.30, 1,217.10 and 400.55

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Solution

The fourth proportional to 812.30, 1,217.10 and 400.55 is: 600.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.30 : 1,217.10 = 400.55 : x
  2. Step 2: Convert to fraction form
    812.30/1,217.10 = 400.55/x
  3. Step 3: Cross multiply
    812.30x = 1,217.10 × 400.55
  4. Step 4: Simplify right side
    812.30x = 487,509.41
  5. Step 5: Solve for x
    x = 487,509.41/812.30
  6. Step 6: Final answer
    x = 600.16

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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.