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Finding the Fourth Proportional to 280.87, 387.45 and 187.66

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Solution

The fourth proportional to 280.87, 387.45 and 187.66 is: 258.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.87 : 387.45 = 187.66 : x
  2. Step 2: Convert to fraction form
    280.87/387.45 = 187.66/x
  3. Step 3: Cross multiply
    280.87x = 387.45 × 187.66
  4. Step 4: Simplify right side
    280.87x = 72,708.87
  5. Step 5: Solve for x
    x = 72,708.87/280.87
  6. Step 6: Final answer
    x = 258.87

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.