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Finding the Fourth Proportional to 115.42, 173.11 and 78.91

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Solution

The fourth proportional to 115.42, 173.11 and 78.91 is: 118.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.42 : 173.11 = 78.91 : x
  2. Step 2: Convert to fraction form
    115.42/173.11 = 78.91/x
  3. Step 3: Cross multiply
    115.42x = 173.11 × 78.91
  4. Step 4: Simplify right side
    115.42x = 13,660.11
  5. Step 5: Solve for x
    x = 13,660.11/115.42
  6. Step 6: Final answer
    x = 118.35

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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.