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Finding the Fourth Proportional to 305.06, 420.66 and 211.91

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Solution

The fourth proportional to 305.06, 420.66 and 211.91 is: 292.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.06 : 420.66 = 211.91 : x
  2. Step 2: Convert to fraction form
    305.06/420.66 = 211.91/x
  3. Step 3: Cross multiply
    305.06x = 420.66 × 211.91
  4. Step 4: Simplify right side
    305.06x = 89,139.96
  5. Step 5: Solve for x
    x = 89,139.96/305.06
  6. Step 6: Final answer
    x = 292.21

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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.