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Finding the Fourth Proportional to 221.17, 305.15 and 154.70

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Solution

The fourth proportional to 221.17, 305.15 and 154.70 is: 213.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.17 : 305.15 = 154.70 : x
  2. Step 2: Convert to fraction form
    221.17/305.15 = 154.70/x
  3. Step 3: Cross multiply
    221.17x = 305.15 × 154.70
  4. Step 4: Simplify right side
    221.17x = 47,208.14
  5. Step 5: Solve for x
    x = 47,208.14/221.17
  6. Step 6: Final answer
    x = 213.45

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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.