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Finding the Fourth Proportional to 131.61, 180.56 and 128.19

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Solution

The fourth proportional to 131.61, 180.56 and 128.19 is: 175.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.61 : 180.56 = 128.19 : x
  2. Step 2: Convert to fraction form
    131.61/180.56 = 128.19/x
  3. Step 3: Cross multiply
    131.61x = 180.56 × 128.19
  4. Step 4: Simplify right side
    131.61x = 23,145.35
  5. Step 5: Solve for x
    x = 23,145.35/131.61
  6. Step 6: Final answer
    x = 175.86

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.