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Finding the Fourth Proportional to 87.20, 130.74 and 59.79

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Solution

The fourth proportional to 87.20, 130.74 and 59.79 is: 89.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.20 : 130.74 = 59.79 : x
  2. Step 2: Convert to fraction form
    87.20/130.74 = 59.79/x
  3. Step 3: Cross multiply
    87.20x = 130.74 × 59.79
  4. Step 4: Simplify right side
    87.20x = 7,816.94
  5. Step 5: Solve for x
    x = 7,816.94/87.20
  6. Step 6: Final answer
    x = 89.64

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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.