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Finding the Fourth Proportional to 399.80, 599.79 and 139.82

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Solution

The fourth proportional to 399.80, 599.79 and 139.82 is: 209.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.80 : 599.79 = 139.82 : x
  2. Step 2: Convert to fraction form
    399.80/599.79 = 139.82/x
  3. Step 3: Cross multiply
    399.80x = 599.79 × 139.82
  4. Step 4: Simplify right side
    399.80x = 83,864.89
  5. Step 5: Solve for x
    x = 83,864.89/399.80
  6. Step 6: Final answer
    x = 209.77

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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.