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Finding the Fourth Proportional to 280.54, 387.14 and 156.21

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Solution

The fourth proportional to 280.54, 387.14 and 156.21 is: 215.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.54 : 387.14 = 156.21 : x
  2. Step 2: Convert to fraction form
    280.54/387.14 = 156.21/x
  3. Step 3: Cross multiply
    280.54x = 387.14 × 156.21
  4. Step 4: Simplify right side
    280.54x = 60,473.20
  5. Step 5: Solve for x
    x = 60,473.20/280.54
  6. Step 6: Final answer
    x = 215.56

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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.