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Finding the Fourth Proportional to 135.78, 202.62 and 128.49

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Solution

The fourth proportional to 135.78, 202.62 and 128.49 is: 191.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.78 : 202.62 = 128.49 : x
  2. Step 2: Convert to fraction form
    135.78/202.62 = 128.49/x
  3. Step 3: Cross multiply
    135.78x = 202.62 × 128.49
  4. Step 4: Simplify right side
    135.78x = 26,034.64
  5. Step 5: Solve for x
    x = 26,034.64/135.78
  6. Step 6: Final answer
    x = 191.74

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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.