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Finding the Fourth Proportional to 280.05, 386.44 and 155.71

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Solution

The fourth proportional to 280.05, 386.44 and 155.71 is: 214.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.05 : 386.44 = 155.71 : x
  2. Step 2: Convert to fraction form
    280.05/386.44 = 155.71/x
  3. Step 3: Cross multiply
    280.05x = 386.44 × 155.71
  4. Step 4: Simplify right side
    280.05x = 60,171.03
  5. Step 5: Solve for x
    x = 60,171.03/280.05
  6. Step 6: Final answer
    x = 214.86

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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.