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Finding the Fourth Proportional to 112.89, 169.17 and 85.45

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Solution

The fourth proportional to 112.89, 169.17 and 85.45 is: 128.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.89 : 169.17 = 85.45 : x
  2. Step 2: Convert to fraction form
    112.89/169.17 = 85.45/x
  3. Step 3: Cross multiply
    112.89x = 169.17 × 85.45
  4. Step 4: Simplify right side
    112.89x = 14,454.52
  5. Step 5: Solve for x
    x = 14,454.52/112.89
  6. Step 6: Final answer
    x = 128.05

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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.