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Finding the Fourth Proportional to 305.70, 421.97 and 211.22

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Solution

The fourth proportional to 305.70, 421.97 and 211.22 is: 291.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.70 : 421.97 = 211.22 : x
  2. Step 2: Convert to fraction form
    305.70/421.97 = 211.22/x
  3. Step 3: Cross multiply
    305.70x = 421.97 × 211.22
  4. Step 4: Simplify right side
    305.70x = 89,129.29
  5. Step 5: Solve for x
    x = 89,129.29/305.70
  6. Step 6: Final answer
    x = 291.55

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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.