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Finding the Fourth Proportional to 190.30, 285.40 and 129.42

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Solution

The fourth proportional to 190.30, 285.40 and 129.42 is: 194.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.30 : 285.40 = 129.42 : x
  2. Step 2: Convert to fraction form
    190.30/285.40 = 129.42/x
  3. Step 3: Cross multiply
    190.30x = 285.40 × 129.42
  4. Step 4: Simplify right side
    190.30x = 36,936.47
  5. Step 5: Solve for x
    x = 36,936.47/190.30
  6. Step 6: Final answer
    x = 194.10

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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.