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Finding the Fourth Proportional to 280.15, 386.40 and 186.85

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Solution

The fourth proportional to 280.15, 386.40 and 186.85 is: 257.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.15 : 386.40 = 186.85 : x
  2. Step 2: Convert to fraction form
    280.15/386.40 = 186.85/x
  3. Step 3: Cross multiply
    280.15x = 386.40 × 186.85
  4. Step 4: Simplify right side
    280.15x = 72,198.84
  5. Step 5: Solve for x
    x = 72,198.84/280.15
  6. Step 6: Final answer
    x = 257.71

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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.