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Finding the Fourth Proportional to 90.89, 125.25 and 66.28

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Solution

The fourth proportional to 90.89, 125.25 and 66.28 is: 91.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.89 : 125.25 = 66.28 : x
  2. Step 2: Convert to fraction form
    90.89/125.25 = 66.28/x
  3. Step 3: Cross multiply
    90.89x = 125.25 × 66.28
  4. Step 4: Simplify right side
    90.89x = 8,301.57
  5. Step 5: Solve for x
    x = 8,301.57/90.89
  6. Step 6: Final answer
    x = 91.34

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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.