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Finding the Fourth Proportional to 801.28, 1,105.90 and 636.74

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Solution

The fourth proportional to 801.28, 1,105.90 and 636.74 is: 878.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.28 : 1,105.90 = 636.74 : x
  2. Step 2: Convert to fraction form
    801.28/1,105.90 = 636.74/x
  3. Step 3: Cross multiply
    801.28x = 1,105.90 × 636.74
  4. Step 4: Simplify right side
    801.28x = 704,170.77
  5. Step 5: Solve for x
    x = 704,170.77/801.28
  6. Step 6: Final answer
    x = 878.81

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.