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Finding the Fourth Proportional to 187.12, 280.68 and 78.91

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Solution

The fourth proportional to 187.12, 280.68 and 78.91 is: 118.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.12 : 280.68 = 78.91 : x
  2. Step 2: Convert to fraction form
    187.12/280.68 = 78.91/x
  3. Step 3: Cross multiply
    187.12x = 280.68 × 78.91
  4. Step 4: Simplify right side
    187.12x = 22,148.46
  5. Step 5: Solve for x
    x = 22,148.46/187.12
  6. Step 6: Final answer
    x = 118.37

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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.