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Finding the Fourth Proportional to 280.30, 386.78 and 155.95

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Solution

The fourth proportional to 280.30, 386.78 and 155.95 is: 215.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.30 : 386.78 = 155.95 : x
  2. Step 2: Convert to fraction form
    280.30/386.78 = 155.95/x
  3. Step 3: Cross multiply
    280.30x = 386.78 × 155.95
  4. Step 4: Simplify right side
    280.30x = 60,318.63
  5. Step 5: Solve for x
    x = 60,318.63/280.30
  6. Step 6: Final answer
    x = 215.19

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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.