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Finding the Fourth Proportional to 87.35, 130.84 and 56.78

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Solution

The fourth proportional to 87.35, 130.84 and 56.78 is: 85.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.35 : 130.84 = 56.78 : x
  2. Step 2: Convert to fraction form
    87.35/130.84 = 56.78/x
  3. Step 3: Cross multiply
    87.35x = 130.84 × 56.78
  4. Step 4: Simplify right side
    87.35x = 7,429.10
  5. Step 5: Solve for x
    x = 7,429.10/87.35
  6. Step 6: Final answer
    x = 85.05

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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.