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Finding the Fourth Proportional to 87.78, 131.70 and 53.59

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Solution

The fourth proportional to 87.78, 131.70 and 53.59 is: 80.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.78 : 131.70 = 53.59 : x
  2. Step 2: Convert to fraction form
    87.78/131.70 = 53.59/x
  3. Step 3: Cross multiply
    87.78x = 131.70 × 53.59
  4. Step 4: Simplify right side
    87.78x = 7,057.47
  5. Step 5: Solve for x
    x = 7,057.47/87.78
  6. Step 6: Final answer
    x = 80.40

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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.