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Finding the Fourth Proportional to 643.30, 963.60 and 505.69

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Solution

The fourth proportional to 643.30, 963.60 and 505.69 is: 757.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.30 : 963.60 = 505.69 : x
  2. Step 2: Convert to fraction form
    643.30/963.60 = 505.69/x
  3. Step 3: Cross multiply
    643.30x = 963.60 × 505.69
  4. Step 4: Simplify right side
    643.30x = 487,282.88
  5. Step 5: Solve for x
    x = 487,282.88/643.30
  6. Step 6: Final answer
    x = 757.47

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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.