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Finding the Fourth Proportional to 154.19, 212.78 and 85.19

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Solution

The fourth proportional to 154.19, 212.78 and 85.19 is: 117.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.19 : 212.78 = 85.19 : x
  2. Step 2: Convert to fraction form
    154.19/212.78 = 85.19/x
  3. Step 3: Cross multiply
    154.19x = 212.78 × 85.19
  4. Step 4: Simplify right side
    154.19x = 18,126.73
  5. Step 5: Solve for x
    x = 18,126.73/154.19
  6. Step 6: Final answer
    x = 117.56

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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.