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Finding the Fourth Proportional to 398.94, 598.38 and 139.14

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Solution

The fourth proportional to 398.94, 598.38 and 139.14 is: 208.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.94 : 598.38 = 139.14 : x
  2. Step 2: Convert to fraction form
    398.94/598.38 = 139.14/x
  3. Step 3: Cross multiply
    398.94x = 598.38 × 139.14
  4. Step 4: Simplify right side
    398.94x = 83,258.59
  5. Step 5: Solve for x
    x = 83,258.59/398.94
  6. Step 6: Final answer
    x = 208.70

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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.