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Finding the Fourth Proportional to 641.71, 884.71 and 491.89

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Solution

The fourth proportional to 641.71, 884.71 and 491.89 is: 678.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.71 : 884.71 = 491.89 : x
  2. Step 2: Convert to fraction form
    641.71/884.71 = 491.89/x
  3. Step 3: Cross multiply
    641.71x = 884.71 × 491.89
  4. Step 4: Simplify right side
    641.71x = 435,175.64
  5. Step 5: Solve for x
    x = 435,175.64/641.71
  6. Step 6: Final answer
    x = 678.15

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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.