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Finding the Fourth Proportional to 800.78, 1,200.72 and 313.52

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Solution

The fourth proportional to 800.78, 1,200.72 and 313.52 is: 470.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    800.78 : 1,200.72 = 313.52 : x
  2. Step 2: Convert to fraction form
    800.78/1,200.72 = 313.52/x
  3. Step 3: Cross multiply
    800.78x = 1,200.72 × 313.52
  4. Step 4: Simplify right side
    800.78x = 376,449.73
  5. Step 5: Solve for x
    x = 376,449.73/800.78
  6. Step 6: Final answer
    x = 470.10

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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.