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Finding the Fourth Proportional to 215.58, 323.03 and 128.71

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Solution

The fourth proportional to 215.58, 323.03 and 128.71 is: 192.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.58 : 323.03 = 128.71 : x
  2. Step 2: Convert to fraction form
    215.58/323.03 = 128.71/x
  3. Step 3: Cross multiply
    215.58x = 323.03 × 128.71
  4. Step 4: Simplify right side
    215.58x = 41,577.19
  5. Step 5: Solve for x
    x = 41,577.19/215.58
  6. Step 6: Final answer
    x = 192.86

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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.