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Finding the Fourth Proportional to 280.38, 386.73 and 258.78

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Solution

The fourth proportional to 280.38, 386.73 and 258.78 is: 356.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.38 : 386.73 = 258.78 : x
  2. Step 2: Convert to fraction form
    280.38/386.73 = 258.78/x
  3. Step 3: Cross multiply
    280.38x = 386.73 × 258.78
  4. Step 4: Simplify right side
    280.38x = 100,077.99
  5. Step 5: Solve for x
    x = 100,077.99/280.38
  6. Step 6: Final answer
    x = 356.94

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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.