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Finding the Fourth Proportional to 518.20, 776.80 and 209.98

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Solution

The fourth proportional to 518.20, 776.80 and 209.98 is: 314.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.20 : 776.80 = 209.98 : x
  2. Step 2: Convert to fraction form
    518.20/776.80 = 209.98/x
  3. Step 3: Cross multiply
    518.20x = 776.80 × 209.98
  4. Step 4: Simplify right side
    518.20x = 163,112.46
  5. Step 5: Solve for x
    x = 163,112.46/518.20
  6. Step 6: Final answer
    x = 314.77

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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.