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Finding the Fourth Proportional to 643.62, 963.80 and 515.10

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Solution

The fourth proportional to 643.62, 963.80 and 515.10 is: 771.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.62 : 963.80 = 515.10 : x
  2. Step 2: Convert to fraction form
    643.62/963.80 = 515.10/x
  3. Step 3: Cross multiply
    643.62x = 963.80 × 515.10
  4. Step 4: Simplify right side
    643.62x = 496,453.38
  5. Step 5: Solve for x
    x = 496,453.38/643.62
  6. Step 6: Final answer
    x = 771.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.