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Finding the Fourth Proportional to 137.46, 205.21 and 128.48

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Solution

The fourth proportional to 137.46, 205.21 and 128.48 is: 191.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.46 : 205.21 = 128.48 : x
  2. Step 2: Convert to fraction form
    137.46/205.21 = 128.48/x
  3. Step 3: Cross multiply
    137.46x = 205.21 × 128.48
  4. Step 4: Simplify right side
    137.46x = 26,365.57
  5. Step 5: Solve for x
    x = 26,365.57/137.46
  6. Step 6: Final answer
    x = 191.81

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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.