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Finding the Fourth Proportional to 239.50, 330.30 and 215.20

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Solution

The fourth proportional to 239.50, 330.30 and 215.20 is: 296.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    239.50 : 330.30 = 215.20 : x
  2. Step 2: Convert to fraction form
    239.50/330.30 = 215.20/x
  3. Step 3: Cross multiply
    239.50x = 330.30 × 215.20
  4. Step 4: Simplify right side
    239.50x = 71,079.73
  5. Step 5: Solve for x
    x = 71,079.73/239.50
  6. Step 6: Final answer
    x = 296.79

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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.