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Finding the Fourth Proportional to 288.61, 398.30 and 215.12

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Solution

The fourth proportional to 288.61, 398.30 and 215.12 is: 296.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.61 : 398.30 = 215.12 : x
  2. Step 2: Convert to fraction form
    288.61/398.30 = 215.12/x
  3. Step 3: Cross multiply
    288.61x = 398.30 × 215.12
  4. Step 4: Simplify right side
    288.61x = 85,682.22
  5. Step 5: Solve for x
    x = 85,682.22/288.61
  6. Step 6: Final answer
    x = 296.88

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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.