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Finding the Fourth Proportional to 812.10, 1,215.99 and 487.02

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Solution

The fourth proportional to 812.10, 1,215.99 and 487.02 is: 729.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.10 : 1,215.99 = 487.02 : x
  2. Step 2: Convert to fraction form
    812.10/1,215.99 = 487.02/x
  3. Step 3: Cross multiply
    812.10x = 1,215.99 × 487.02
  4. Step 4: Simplify right side
    812.10x = 592,211.45
  5. Step 5: Solve for x
    x = 592,211.45/812.10
  6. Step 6: Final answer
    x = 729.23

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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.