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Finding the Fourth Proportional to 288.20, 398.15 and 188.85

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Solution

The fourth proportional to 288.20, 398.15 and 188.85 is: 260.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.20 : 398.15 = 188.85 : x
  2. Step 2: Convert to fraction form
    288.20/398.15 = 188.85/x
  3. Step 3: Cross multiply
    288.20x = 398.15 × 188.85
  4. Step 4: Simplify right side
    288.20x = 75,192.96
  5. Step 5: Solve for x
    x = 75,192.96/288.20
  6. Step 6: Final answer
    x = 260.90

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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.