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Finding the Fourth Proportional to 215.52, 323.31 and 78.69

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Solution

The fourth proportional to 215.52, 323.31 and 78.69 is: 118.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.52 : 323.31 = 78.69 : x
  2. Step 2: Convert to fraction form
    215.52/323.31 = 78.69/x
  3. Step 3: Cross multiply
    215.52x = 323.31 × 78.69
  4. Step 4: Simplify right side
    215.52x = 25,441.26
  5. Step 5: Solve for x
    x = 25,441.26/215.52
  6. Step 6: Final answer
    x = 118.05

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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.