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Finding the Fourth Proportional to 131.62, 198.28 and 128.38

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Solution

The fourth proportional to 131.62, 198.28 and 128.38 is: 193.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.62 : 198.28 = 128.38 : x
  2. Step 2: Convert to fraction form
    131.62/198.28 = 128.38/x
  3. Step 3: Cross multiply
    131.62x = 198.28 × 128.38
  4. Step 4: Simplify right side
    131.62x = 25,455.19
  5. Step 5: Solve for x
    x = 25,455.19/131.62
  6. Step 6: Final answer
    x = 193.40

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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.