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Finding the Fourth Proportional to 90.80, 131.50 and 90.80

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Solution

The fourth proportional to 90.80, 131.50 and 90.80 is: 131.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.80 : 131.50 = 90.80 : x
  2. Step 2: Convert to fraction form
    90.80/131.50 = 90.80/x
  3. Step 3: Cross multiply
    90.80x = 131.50 × 90.80
  4. Step 4: Simplify right side
    90.80x = 11,940.20
  5. Step 5: Solve for x
    x = 11,940.20/90.80
  6. Step 6: Final answer
    x = 131.50

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Why These Related Problems?

These problems maintain the same ratio (1.45) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.