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Finding the Fourth Proportional to 131.40, 197.19 and 90.87

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Solution

The fourth proportional to 131.40, 197.19 and 90.87 is: 136.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.40 : 197.19 = 90.87 : x
  2. Step 2: Convert to fraction form
    131.40/197.19 = 90.87/x
  3. Step 3: Cross multiply
    131.40x = 197.19 × 90.87
  4. Step 4: Simplify right side
    131.40x = 17,917.67
  5. Step 5: Solve for x
    x = 17,917.67/131.40
  6. Step 6: Final answer
    x = 136.36

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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.