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Finding the Fourth Proportional to 399.20, 598.77 and 139.10

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Solution

The fourth proportional to 399.20, 598.77 and 139.10 is: 208.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.20 : 598.77 = 139.10 : x
  2. Step 2: Convert to fraction form
    399.20/598.77 = 139.10/x
  3. Step 3: Cross multiply
    399.20x = 598.77 × 139.10
  4. Step 4: Simplify right side
    399.20x = 83,285.91
  5. Step 5: Solve for x
    x = 83,285.91/399.20
  6. Step 6: Final answer
    x = 208.63

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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.