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Finding the Fourth Proportional to 679.78, 938.08 and 385.03

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Solution

The fourth proportional to 679.78, 938.08 and 385.03 is: 531.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.78 : 938.08 = 385.03 : x
  2. Step 2: Convert to fraction form
    679.78/938.08 = 385.03/x
  3. Step 3: Cross multiply
    679.78x = 938.08 × 385.03
  4. Step 4: Simplify right side
    679.78x = 361,188.94
  5. Step 5: Solve for x
    x = 361,188.94/679.78
  6. Step 6: Final answer
    x = 531.33

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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.