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Finding the Fourth Proportional to 112.20, 154.78 and 70.72

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Solution

The fourth proportional to 112.20, 154.78 and 70.72 is: 97.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.20 : 154.78 = 70.72 : x
  2. Step 2: Convert to fraction form
    112.20/154.78 = 70.72/x
  3. Step 3: Cross multiply
    112.20x = 154.78 × 70.72
  4. Step 4: Simplify right side
    112.20x = 10,946.04
  5. Step 5: Solve for x
    x = 10,946.04/112.20
  6. Step 6: Final answer
    x = 97.56

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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.