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Finding the Fourth Proportional to 840.78, 1,160.30 and 467.78

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Solution

The fourth proportional to 840.78, 1,160.30 and 467.78 is: 645.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.78 : 1,160.30 = 467.78 : x
  2. Step 2: Convert to fraction form
    840.78/1,160.30 = 467.78/x
  3. Step 3: Cross multiply
    840.78x = 1,160.30 × 467.78
  4. Step 4: Simplify right side
    840.78x = 542,765.13
  5. Step 5: Solve for x
    x = 542,765.13/840.78
  6. Step 6: Final answer
    x = 645.55

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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.