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Finding the Fourth Proportional to 87.13, 120.15 and 56.00

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Solution

The fourth proportional to 87.13, 120.15 and 56.00 is: 77.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.13 : 120.15 = 56.00 : x
  2. Step 2: Convert to fraction form
    87.13/120.15 = 56.00/x
  3. Step 3: Cross multiply
    87.13x = 120.15 × 56.00
  4. Step 4: Simplify right side
    87.13x = 6,728.02
  5. Step 5: Solve for x
    x = 6,728.02/87.13
  6. Step 6: Final answer
    x = 77.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.