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Finding the Fourth Proportional to 112.49, 155.30 and 81.38

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Solution

The fourth proportional to 112.49, 155.30 and 81.38 is: 112.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.49 : 155.30 = 81.38 : x
  2. Step 2: Convert to fraction form
    112.49/155.30 = 81.38/x
  3. Step 3: Cross multiply
    112.49x = 155.30 × 81.38
  4. Step 4: Simplify right side
    112.49x = 12,637.74
  5. Step 5: Solve for x
    x = 12,637.74/112.49
  6. Step 6: Final answer
    x = 112.34

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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.