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Finding the Fourth Proportional to 130.85, 197.31 and 128.42

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Solution

The fourth proportional to 130.85, 197.31 and 128.42 is: 193.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.85 : 197.31 = 128.42 : x
  2. Step 2: Convert to fraction form
    130.85/197.31 = 128.42/x
  3. Step 3: Cross multiply
    130.85x = 197.31 × 128.42
  4. Step 4: Simplify right side
    130.85x = 25,337.56
  5. Step 5: Solve for x
    x = 25,337.56/130.85
  6. Step 6: Final answer
    x = 193.65

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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.