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Finding the Fourth Proportional to 399.31, 598.30 and 139.17

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Solution

The fourth proportional to 399.31, 598.30 and 139.17 is: 208.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.31 : 598.30 = 139.17 : x
  2. Step 2: Convert to fraction form
    399.31/598.30 = 139.17/x
  3. Step 3: Cross multiply
    399.31x = 598.30 × 139.17
  4. Step 4: Simplify right side
    399.31x = 83,265.41
  5. Step 5: Solve for x
    x = 83,265.41/399.31
  6. Step 6: Final answer
    x = 208.52

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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.