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Finding the Fourth Proportional to 815.38, 1,222.56 and 398.08

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Solution

The fourth proportional to 815.38, 1,222.56 and 398.08 is: 596.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.38 : 1,222.56 = 398.08 : x
  2. Step 2: Convert to fraction form
    815.38/1,222.56 = 398.08/x
  3. Step 3: Cross multiply
    815.38x = 1,222.56 × 398.08
  4. Step 4: Simplify right side
    815.38x = 486,676.68
  5. Step 5: Solve for x
    x = 486,676.68/815.38
  6. Step 6: Final answer
    x = 596.87

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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.