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Finding the Fourth Proportional to 87.49, 131.80 and 66.25

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Solution

The fourth proportional to 87.49, 131.80 and 66.25 is: 99.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.49 : 131.80 = 66.25 : x
  2. Step 2: Convert to fraction form
    87.49/131.80 = 66.25/x
  3. Step 3: Cross multiply
    87.49x = 131.80 × 66.25
  4. Step 4: Simplify right side
    87.49x = 8,731.75
  5. Step 5: Solve for x
    x = 8,731.75/87.49
  6. Step 6: Final answer
    x = 99.80

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.