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Finding the Fourth Proportional to 815.90, 1,225.49 and 487.49

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Solution

The fourth proportional to 815.90, 1,225.49 and 487.49 is: 732.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.90 : 1,225.49 = 487.49 : x
  2. Step 2: Convert to fraction form
    815.90/1,225.49 = 487.49/x
  3. Step 3: Cross multiply
    815.90x = 1,225.49 × 487.49
  4. Step 4: Simplify right side
    815.90x = 597,405.56
  5. Step 5: Solve for x
    x = 597,405.56/815.90
  6. Step 6: Final answer
    x = 732.21

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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.