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Finding the Fourth Proportional to 280.31, 386.85 and 155.98

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Solution

The fourth proportional to 280.31, 386.85 and 155.98 is: 215.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.31 : 386.85 = 155.98 : x
  2. Step 2: Convert to fraction form
    280.31/386.85 = 155.98/x
  3. Step 3: Cross multiply
    280.31x = 386.85 × 155.98
  4. Step 4: Simplify right side
    280.31x = 60,338.93
  5. Step 5: Solve for x
    x = 60,338.93/280.31
  6. Step 6: Final answer
    x = 215.26

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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.