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Finding the Fourth Proportional to 280.08, 386.49 and 155.70

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Solution

The fourth proportional to 280.08, 386.49 and 155.70 is: 214.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.08 : 386.49 = 155.70 : x
  2. Step 2: Convert to fraction form
    280.08/386.49 = 155.70/x
  3. Step 3: Cross multiply
    280.08x = 386.49 × 155.70
  4. Step 4: Simplify right side
    280.08x = 60,176.49
  5. Step 5: Solve for x
    x = 60,176.49/280.08
  6. Step 6: Final answer
    x = 214.85

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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.