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Finding the Fourth Proportional to 90.94, 125.40 and 72.31

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Solution

The fourth proportional to 90.94, 125.40 and 72.31 is: 99.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.94 : 125.40 = 72.31 : x
  2. Step 2: Convert to fraction form
    90.94/125.40 = 72.31/x
  3. Step 3: Cross multiply
    90.94x = 125.40 × 72.31
  4. Step 4: Simplify right side
    90.94x = 9,067.46
  5. Step 5: Solve for x
    x = 9,067.46/90.94
  6. Step 6: Final answer
    x = 99.71

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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.