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Finding the Fourth Proportional to 190.31, 285.18 and 128.54

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Solution

The fourth proportional to 190.31, 285.18 and 128.54 is: 192.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.31 : 285.18 = 128.54 : x
  2. Step 2: Convert to fraction form
    190.31/285.18 = 128.54/x
  3. Step 3: Cross multiply
    190.31x = 285.18 × 128.54
  4. Step 4: Simplify right side
    190.31x = 36,656.57
  5. Step 5: Solve for x
    x = 36,656.57/190.31
  6. Step 6: Final answer
    x = 192.61

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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.