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Finding the Fourth Proportional to 641.26, 884.68 and 491.91

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Solution

The fourth proportional to 641.26, 884.68 and 491.91 is: 678.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.26 : 884.68 = 491.91 : x
  2. Step 2: Convert to fraction form
    641.26/884.68 = 491.91/x
  3. Step 3: Cross multiply
    641.26x = 884.68 × 491.91
  4. Step 4: Simplify right side
    641.26x = 435,178.27
  5. Step 5: Solve for x
    x = 435,178.27/641.26
  6. Step 6: Final answer
    x = 678.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.