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Finding the Fourth Proportional to 298.40, 411.52 and 215.20

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Solution

The fourth proportional to 298.40, 411.52 and 215.20 is: 296.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.40 : 411.52 = 215.20 : x
  2. Step 2: Convert to fraction form
    298.40/411.52 = 215.20/x
  3. Step 3: Cross multiply
    298.40x = 411.52 × 215.20
  4. Step 4: Simplify right side
    298.40x = 88,559.10
  5. Step 5: Solve for x
    x = 88,559.10/298.40
  6. Step 6: Final answer
    x = 296.78

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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.