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Finding the Fourth Proportional to 190.29, 285.05 and 128.40

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Solution

The fourth proportional to 190.29, 285.05 and 128.40 is: 192.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.29 : 285.05 = 128.40 : x
  2. Step 2: Convert to fraction form
    190.29/285.05 = 128.40/x
  3. Step 3: Cross multiply
    190.29x = 285.05 × 128.40
  4. Step 4: Simplify right side
    190.29x = 36,599.78
  5. Step 5: Solve for x
    x = 36,599.78/190.29
  6. Step 6: Final answer
    x = 192.34

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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.