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Finding the Fourth Proportional to 804.78, 1,207.50 and 311.31

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Solution

The fourth proportional to 804.78, 1,207.50 and 311.31 is: 467.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    804.78 : 1,207.50 = 311.31 : x
  2. Step 2: Convert to fraction form
    804.78/1,207.50 = 311.31/x
  3. Step 3: Cross multiply
    804.78x = 1,207.50 × 311.31
  4. Step 4: Simplify right side
    804.78x = 375,906.83
  5. Step 5: Solve for x
    x = 375,906.83/804.78
  6. Step 6: Final answer
    x = 467.09

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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.