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Finding the Fourth Proportional to 398.78, 597.39 and 261.41

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Solution

The fourth proportional to 398.78, 597.39 and 261.41 is: 391.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.78 : 597.39 = 261.41 : x
  2. Step 2: Convert to fraction form
    398.78/597.39 = 261.41/x
  3. Step 3: Cross multiply
    398.78x = 597.39 × 261.41
  4. Step 4: Simplify right side
    398.78x = 156,159.43
  5. Step 5: Solve for x
    x = 156,159.43/398.78
  6. Step 6: Final answer
    x = 391.60

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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.