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Finding the Fourth Proportional to 131.51, 196.86 and 85.76

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Solution

The fourth proportional to 131.51, 196.86 and 85.76 is: 128.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.51 : 196.86 = 85.76 : x
  2. Step 2: Convert to fraction form
    131.51/196.86 = 85.76/x
  3. Step 3: Cross multiply
    131.51x = 196.86 × 85.76
  4. Step 4: Simplify right side
    131.51x = 16,882.71
  5. Step 5: Solve for x
    x = 16,882.71/131.51
  6. Step 6: Final answer
    x = 128.38

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.