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Finding the Fourth Proportional to 280.83, 421.40 and 143.54

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Solution

The fourth proportional to 280.83, 421.40 and 143.54 is: 215.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.83 : 421.40 = 143.54 : x
  2. Step 2: Convert to fraction form
    280.83/421.40 = 143.54/x
  3. Step 3: Cross multiply
    280.83x = 421.40 × 143.54
  4. Step 4: Simplify right side
    280.83x = 60,487.59
  5. Step 5: Solve for x
    x = 60,487.59/280.83
  6. Step 6: Final answer
    x = 215.39

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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.