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Finding the Fourth Proportional to 215.49, 323.04 and 128.85

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Solution

The fourth proportional to 215.49, 323.04 and 128.85 is: 193.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.49 : 323.04 = 128.85 : x
  2. Step 2: Convert to fraction form
    215.49/323.04 = 128.85/x
  3. Step 3: Cross multiply
    215.49x = 323.04 × 128.85
  4. Step 4: Simplify right side
    215.49x = 41,623.70
  5. Step 5: Solve for x
    x = 41,623.70/215.49
  6. Step 6: Final answer
    x = 193.16

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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.