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Finding the Fourth Proportional to 642.61, 965.45 and 411.94

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Solution

The fourth proportional to 642.61, 965.45 and 411.94 is: 618.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.61 : 965.45 = 411.94 : x
  2. Step 2: Convert to fraction form
    642.61/965.45 = 411.94/x
  3. Step 3: Cross multiply
    642.61x = 965.45 × 411.94
  4. Step 4: Simplify right side
    642.61x = 397,711.27
  5. Step 5: Solve for x
    x = 397,711.27/642.61
  6. Step 6: Final answer
    x = 618.90

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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.