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Finding the Fourth Proportional to 230.13, 345.21 and 85.90

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Solution

The fourth proportional to 230.13, 345.21 and 85.90 is: 128.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    230.13 : 345.21 = 85.90 : x
  2. Step 2: Convert to fraction form
    230.13/345.21 = 85.90/x
  3. Step 3: Cross multiply
    230.13x = 345.21 × 85.90
  4. Step 4: Simplify right side
    230.13x = 29,653.54
  5. Step 5: Solve for x
    x = 29,653.54/230.13
  6. Step 6: Final answer
    x = 128.86

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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.