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Finding the Fourth Proportional to 112.87, 169.17 and 78.45

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Solution

The fourth proportional to 112.87, 169.17 and 78.45 is: 117.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.87 : 169.17 = 78.45 : x
  2. Step 2: Convert to fraction form
    112.87/169.17 = 78.45/x
  3. Step 3: Cross multiply
    112.87x = 169.17 × 78.45
  4. Step 4: Simplify right side
    112.87x = 13,270.90
  5. Step 5: Solve for x
    x = 13,270.90/112.87
  6. Step 6: Final answer
    x = 117.58

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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.