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Finding the Fourth Proportional to 280.71, 387.41 and 156.38

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Solution

The fourth proportional to 280.71, 387.41 and 156.38 is: 215.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 387.41 = 156.38 : x
  2. Step 2: Convert to fraction form
    280.71/387.41 = 156.38/x
  3. Step 3: Cross multiply
    280.71x = 387.41 × 156.38
  4. Step 4: Simplify right side
    280.71x = 60,580.46
  5. Step 5: Solve for x
    x = 60,580.46/280.71
  6. Step 6: Final answer
    x = 215.81

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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.