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Finding the Fourth Proportional to 641.86, 961.71 and 505.06

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Solution

The fourth proportional to 641.86, 961.71 and 505.06 is: 756.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.86 : 961.71 = 505.06 : x
  2. Step 2: Convert to fraction form
    641.86/961.71 = 505.06/x
  3. Step 3: Cross multiply
    641.86x = 961.71 × 505.06
  4. Step 4: Simplify right side
    641.86x = 485,721.25
  5. Step 5: Solve for x
    x = 485,721.25/641.86
  6. Step 6: Final answer
    x = 756.74

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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.