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Finding the Fourth Proportional to 305.28, 421.84 and 217.80

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Solution

The fourth proportional to 305.28, 421.84 and 217.80 is: 300.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.28 : 421.84 = 217.80 : x
  2. Step 2: Convert to fraction form
    305.28/421.84 = 217.80/x
  3. Step 3: Cross multiply
    305.28x = 421.84 × 217.80
  4. Step 4: Simplify right side
    305.28x = 91,876.75
  5. Step 5: Solve for x
    x = 91,876.75/305.28
  6. Step 6: Final answer
    x = 300.96

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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.