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Finding the Fourth Proportional to 642.79, 963.64 and 436.78

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Solution

The fourth proportional to 642.79, 963.64 and 436.78 is: 654.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.79 : 963.64 = 436.78 : x
  2. Step 2: Convert to fraction form
    642.79/963.64 = 436.78/x
  3. Step 3: Cross multiply
    642.79x = 963.64 × 436.78
  4. Step 4: Simplify right side
    642.79x = 420,898.68
  5. Step 5: Solve for x
    x = 420,898.68/642.79
  6. Step 6: Final answer
    x = 654.80

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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.