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Finding the Fourth Proportional to 123.85, 170.85 and 109.86

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Solution

The fourth proportional to 123.85, 170.85 and 109.86 is: 151.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.85 : 170.85 = 109.86 : x
  2. Step 2: Convert to fraction form
    123.85/170.85 = 109.86/x
  3. Step 3: Cross multiply
    123.85x = 170.85 × 109.86
  4. Step 4: Simplify right side
    123.85x = 18,769.58
  5. Step 5: Solve for x
    x = 18,769.58/123.85
  6. Step 6: Final answer
    x = 151.55

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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.