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Finding the Fourth Proportional to 215.69, 323.46 and 78.70

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Solution

The fourth proportional to 215.69, 323.46 and 78.70 is: 118.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.69 : 323.46 = 78.70 : x
  2. Step 2: Convert to fraction form
    215.69/323.46 = 78.70/x
  3. Step 3: Cross multiply
    215.69x = 323.46 × 78.70
  4. Step 4: Simplify right side
    215.69x = 25,456.30
  5. Step 5: Solve for x
    x = 25,456.30/215.69
  6. Step 6: Final answer
    x = 118.02

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.