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Finding the Fourth Proportional to 190.80, 263.22 and 128.70

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Solution

The fourth proportional to 190.80, 263.22 and 128.70 is: 177.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.80 : 263.22 = 128.70 : x
  2. Step 2: Convert to fraction form
    190.80/263.22 = 128.70/x
  3. Step 3: Cross multiply
    190.80x = 263.22 × 128.70
  4. Step 4: Simplify right side
    190.80x = 33,876.41
  5. Step 5: Solve for x
    x = 33,876.41/190.80
  6. Step 6: Final answer
    x = 177.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.