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Finding the Fourth Proportional to 801.12, 1,201.28 and 338.72

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Solution

The fourth proportional to 801.12, 1,201.28 and 338.72 is: 507.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.12 : 1,201.28 = 338.72 : x
  2. Step 2: Convert to fraction form
    801.12/1,201.28 = 338.72/x
  3. Step 3: Cross multiply
    801.12x = 1,201.28 × 338.72
  4. Step 4: Simplify right side
    801.12x = 406,897.56
  5. Step 5: Solve for x
    x = 406,897.56/801.12
  6. Step 6: Final answer
    x = 507.91

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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.