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Finding the Fourth Proportional to 87.42, 131.08 and 53.20

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Solution

The fourth proportional to 87.42, 131.08 and 53.20 is: 79.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.42 : 131.08 = 53.20 : x
  2. Step 2: Convert to fraction form
    87.42/131.08 = 53.20/x
  3. Step 3: Cross multiply
    87.42x = 131.08 × 53.20
  4. Step 4: Simplify right side
    87.42x = 6,973.46
  5. Step 5: Solve for x
    x = 6,973.46/87.42
  6. Step 6: Final answer
    x = 79.77

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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.