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Finding the Fourth Proportional to 305.09, 420.59 and 217.61

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Solution

The fourth proportional to 305.09, 420.59 and 217.61 is: 299.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.09 : 420.59 = 217.61 : x
  2. Step 2: Convert to fraction form
    305.09/420.59 = 217.61/x
  3. Step 3: Cross multiply
    305.09x = 420.59 × 217.61
  4. Step 4: Simplify right side
    305.09x = 91,523.50
  5. Step 5: Solve for x
    x = 91,523.50/305.09
  6. Step 6: Final answer
    x = 299.99

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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.