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Finding the Fourth Proportional to 680.79, 939.39 and 385.98

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Solution

The fourth proportional to 680.79, 939.39 and 385.98 is: 532.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.79 : 939.39 = 385.98 : x
  2. Step 2: Convert to fraction form
    680.79/939.39 = 385.98/x
  3. Step 3: Cross multiply
    680.79x = 939.39 × 385.98
  4. Step 4: Simplify right side
    680.79x = 362,585.75
  5. Step 5: Solve for x
    x = 362,585.75/680.79
  6. Step 6: Final answer
    x = 532.60

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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.