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Finding the Fourth Proportional to 398.58, 598.02 and 138.60

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Solution

The fourth proportional to 398.58, 598.02 and 138.60 is: 207.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.58 : 598.02 = 138.60 : x
  2. Step 2: Convert to fraction form
    398.58/598.02 = 138.60/x
  3. Step 3: Cross multiply
    398.58x = 598.02 × 138.60
  4. Step 4: Simplify right side
    398.58x = 82,885.57
  5. Step 5: Solve for x
    x = 82,885.57/398.58
  6. Step 6: Final answer
    x = 207.95

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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.