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Finding the Fourth Proportional to 169.85, 254.64 and 78.61

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Solution

The fourth proportional to 169.85, 254.64 and 78.61 is: 117.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    169.85 : 254.64 = 78.61 : x
  2. Step 2: Convert to fraction form
    169.85/254.64 = 78.61/x
  3. Step 3: Cross multiply
    169.85x = 254.64 × 78.61
  4. Step 4: Simplify right side
    169.85x = 20,017.25
  5. Step 5: Solve for x
    x = 20,017.25/169.85
  6. Step 6: Final answer
    x = 117.85

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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.