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Finding the Fourth Proportional to 280.85, 420.83 and 143.69

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Solution

The fourth proportional to 280.85, 420.83 and 143.69 is: 215.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.85 : 420.83 = 143.69 : x
  2. Step 2: Convert to fraction form
    280.85/420.83 = 143.69/x
  3. Step 3: Cross multiply
    280.85x = 420.83 × 143.69
  4. Step 4: Simplify right side
    280.85x = 60,468.34
  5. Step 5: Solve for x
    x = 60,468.34/280.85
  6. Step 6: Final answer
    x = 215.30

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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.