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Finding the Fourth Proportional to 154.15, 212.71 and 84.20

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Solution

The fourth proportional to 154.15, 212.71 and 84.20 is: 116.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.15 : 212.71 = 84.20 : x
  2. Step 2: Convert to fraction form
    154.15/212.71 = 84.20/x
  3. Step 3: Cross multiply
    154.15x = 212.71 × 84.20
  4. Step 4: Simplify right side
    154.15x = 17,910.92
  5. Step 5: Solve for x
    x = 17,910.92/154.15
  6. Step 6: Final answer
    x = 116.19

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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.