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Finding the Fourth Proportional to 280.87, 421.21 and 118.51

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Solution

The fourth proportional to 280.87, 421.21 and 118.51 is: 177.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.87 : 421.21 = 118.51 : x
  2. Step 2: Convert to fraction form
    280.87/421.21 = 118.51/x
  3. Step 3: Cross multiply
    280.87x = 421.21 × 118.51
  4. Step 4: Simplify right side
    280.87x = 49,917.60
  5. Step 5: Solve for x
    x = 49,917.60/280.87
  6. Step 6: Final answer
    x = 177.72

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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.