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Finding the Fourth Proportional to 280.80, 421.34 and 220.46

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Solution

The fourth proportional to 280.80, 421.34 and 220.46 is: 330.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.80 : 421.34 = 220.46 : x
  2. Step 2: Convert to fraction form
    280.80/421.34 = 220.46/x
  3. Step 3: Cross multiply
    280.80x = 421.34 × 220.46
  4. Step 4: Simplify right side
    280.80x = 92,885.41
  5. Step 5: Solve for x
    x = 92,885.41/280.80
  6. Step 6: Final answer
    x = 330.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.