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Finding the Fourth Proportional to 680.48, 939.12 and 385.64

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Solution

The fourth proportional to 680.48, 939.12 and 385.64 is: 532.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.48 : 939.12 = 385.64 : x
  2. Step 2: Convert to fraction form
    680.48/939.12 = 385.64/x
  3. Step 3: Cross multiply
    680.48x = 939.12 × 385.64
  4. Step 4: Simplify right side
    680.48x = 362,162.24
  5. Step 5: Solve for x
    x = 362,162.24/680.48
  6. Step 6: Final answer
    x = 532.22

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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.