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Finding the Fourth Proportional to 800.75, 1,200.99 and 338.78

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Solution

The fourth proportional to 800.75, 1,200.99 and 338.78 is: 508.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    800.75 : 1,200.99 = 338.78 : x
  2. Step 2: Convert to fraction form
    800.75/1,200.99 = 338.78/x
  3. Step 3: Cross multiply
    800.75x = 1,200.99 × 338.78
  4. Step 4: Simplify right side
    800.75x = 406,871.39
  5. Step 5: Solve for x
    x = 406,871.39/800.75
  6. Step 6: Final answer
    x = 508.11

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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.