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Finding the Fourth Proportional to 280.70, 421.86 and 269.90

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Solution

The fourth proportional to 280.70, 421.86 and 269.90 is: 405.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.70 : 421.86 = 269.90 : x
  2. Step 2: Convert to fraction form
    280.70/421.86 = 269.90/x
  3. Step 3: Cross multiply
    280.70x = 421.86 × 269.90
  4. Step 4: Simplify right side
    280.70x = 113,860.01
  5. Step 5: Solve for x
    x = 113,860.01/280.70
  6. Step 6: Final answer
    x = 405.63

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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.