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Finding the Fourth Proportional to 101.80, 140.40 and 90.88

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Solution

The fourth proportional to 101.80, 140.40 and 90.88 is: 125.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.80 : 140.40 = 90.88 : x
  2. Step 2: Convert to fraction form
    101.80/140.40 = 90.88/x
  3. Step 3: Cross multiply
    101.80x = 140.40 × 90.88
  4. Step 4: Simplify right side
    101.80x = 12,759.55
  5. Step 5: Solve for x
    x = 12,759.55/101.80
  6. Step 6: Final answer
    x = 125.34

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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.