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Finding the Fourth Proportional to 131.28, 180.80 and 98.61

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Solution

The fourth proportional to 131.28, 180.80 and 98.61 is: 135.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.28 : 180.80 = 98.61 : x
  2. Step 2: Convert to fraction form
    131.28/180.80 = 98.61/x
  3. Step 3: Cross multiply
    131.28x = 180.80 × 98.61
  4. Step 4: Simplify right side
    131.28x = 17,828.19
  5. Step 5: Solve for x
    x = 17,828.19/131.28
  6. Step 6: Final answer
    x = 135.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.