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Finding the Fourth Proportional to 679.70, 938.02 and 385

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Solution

The fourth proportional to 679.70, 938.02 and 385 is: 531.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.70 : 938.02 = 385 : x
  2. Step 2: Convert to fraction form
    679.70/938.02 = 385/x
  3. Step 3: Cross multiply
    679.70x = 938.02 × 385
  4. Step 4: Simplify right side
    679.70x = 361,137.70
  5. Step 5: Solve for x
    x = 361,137.70/679.70
  6. Step 6: Final answer
    x = 531.32

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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.