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Finding the Fourth Proportional to 672.78, 928.56 and 378.12

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Solution

The fourth proportional to 672.78, 928.56 and 378.12 is: 521.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    672.78 : 928.56 = 378.12 : x
  2. Step 2: Convert to fraction form
    672.78/928.56 = 378.12/x
  3. Step 3: Cross multiply
    672.78x = 928.56 × 378.12
  4. Step 4: Simplify right side
    672.78x = 351,107.11
  5. Step 5: Solve for x
    x = 351,107.11/672.78
  6. Step 6: Final answer
    x = 521.88

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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.