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Finding the Fourth Proportional to 698.28, 963.60 and 387.78

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Solution

The fourth proportional to 698.28, 963.60 and 387.78 is: 535.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.28 : 963.60 = 387.78 : x
  2. Step 2: Convert to fraction form
    698.28/963.60 = 387.78/x
  3. Step 3: Cross multiply
    698.28x = 963.60 × 387.78
  4. Step 4: Simplify right side
    698.28x = 373,664.81
  5. Step 5: Solve for x
    x = 373,664.81/698.28
  6. Step 6: Final answer
    x = 535.12

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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.