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Finding the Fourth Proportional to 128.23, 191.11 and 123.15

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Solution

The fourth proportional to 128.23, 191.11 and 123.15 is: 183.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.23 : 191.11 = 123.15 : x
  2. Step 2: Convert to fraction form
    128.23/191.11 = 123.15/x
  3. Step 3: Cross multiply
    128.23x = 191.11 × 123.15
  4. Step 4: Simplify right side
    128.23x = 23,535.20
  5. Step 5: Solve for x
    x = 23,535.20/128.23
  6. Step 6: Final answer
    x = 183.54

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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.