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Finding the Fourth Proportional to 215.15, 321.16 and 189.20

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Solution

The fourth proportional to 215.15, 321.16 and 189.20 is: 282.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.15 : 321.16 = 189.20 : x
  2. Step 2: Convert to fraction form
    215.15/321.16 = 189.20/x
  3. Step 3: Cross multiply
    215.15x = 321.16 × 189.20
  4. Step 4: Simplify right side
    215.15x = 60,761.39
  5. Step 5: Solve for x
    x = 60,761.39/215.15
  6. Step 6: Final answer
    x = 282.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.