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Finding the Fourth Proportional to 398.98, 598.35 and 138.92

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Solution

The fourth proportional to 398.98, 598.35 and 138.92 is: 208.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.98 : 598.35 = 138.92 : x
  2. Step 2: Convert to fraction form
    398.98/598.35 = 138.92/x
  3. Step 3: Cross multiply
    398.98x = 598.35 × 138.92
  4. Step 4: Simplify right side
    398.98x = 83,119.79
  5. Step 5: Solve for x
    x = 83,119.79/398.98
  6. Step 6: Final answer
    x = 208.33

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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.