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Finding the Fourth Proportional to 915.49, 1,372.42 and 641.71

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Solution

The fourth proportional to 915.49, 1,372.42 and 641.71 is: 961.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    915.49 : 1,372.42 = 641.71 : x
  2. Step 2: Convert to fraction form
    915.49/1,372.42 = 641.71/x
  3. Step 3: Cross multiply
    915.49x = 1,372.42 × 641.71
  4. Step 4: Simplify right side
    915.49x = 880,695.64
  5. Step 5: Solve for x
    x = 880,695.64/915.49
  6. Step 6: Final answer
    x = 961.99

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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.