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Finding the Fourth Proportional to 807.38, 1,211.65 and 287.38

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Solution

The fourth proportional to 807.38, 1,211.65 and 287.38 is: 431.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.38 : 1,211.65 = 287.38 : x
  2. Step 2: Convert to fraction form
    807.38/1,211.65 = 287.38/x
  3. Step 3: Cross multiply
    807.38x = 1,211.65 × 287.38
  4. Step 4: Simplify right side
    807.38x = 348,203.98
  5. Step 5: Solve for x
    x = 348,203.98/807.38
  6. Step 6: Final answer
    x = 431.28

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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.