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Finding the Fourth Proportional to 215.67, 323.12 and 78.63

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Solution

The fourth proportional to 215.67, 323.12 and 78.63 is: 117.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.67 : 323.12 = 78.63 : x
  2. Step 2: Convert to fraction form
    215.67/323.12 = 78.63/x
  3. Step 3: Cross multiply
    215.67x = 323.12 × 78.63
  4. Step 4: Simplify right side
    215.67x = 25,406.53
  5. Step 5: Solve for x
    x = 25,406.53/215.67
  6. Step 6: Final answer
    x = 117.80

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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.