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Finding the Fourth Proportional to 135.40, 204.13 and 128.20

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Solution

The fourth proportional to 135.40, 204.13 and 128.20 is: 193.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.40 : 204.13 = 128.20 : x
  2. Step 2: Convert to fraction form
    135.40/204.13 = 128.20/x
  3. Step 3: Cross multiply
    135.40x = 204.13 × 128.20
  4. Step 4: Simplify right side
    135.40x = 26,169.47
  5. Step 5: Solve for x
    x = 26,169.47/135.40
  6. Step 6: Final answer
    x = 193.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.