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Finding the Fourth Proportional to 87.24, 130.80 and 54.78

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Solution

The fourth proportional to 87.24, 130.80 and 54.78 is: 82.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.24 : 130.80 = 54.78 : x
  2. Step 2: Convert to fraction form
    87.24/130.80 = 54.78/x
  3. Step 3: Cross multiply
    87.24x = 130.80 × 54.78
  4. Step 4: Simplify right side
    87.24x = 7,165.22
  5. Step 5: Solve for x
    x = 7,165.22/87.24
  6. Step 6: Final answer
    x = 82.13

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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.