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Finding the Fourth Proportional to 90.87, 125.53 and 66.42

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Solution

The fourth proportional to 90.87, 125.53 and 66.42 is: 91.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.87 : 125.53 = 66.42 : x
  2. Step 2: Convert to fraction form
    90.87/125.53 = 66.42/x
  3. Step 3: Cross multiply
    90.87x = 125.53 × 66.42
  4. Step 4: Simplify right side
    90.87x = 8,337.07
  5. Step 5: Solve for x
    x = 8,337.07/90.87
  6. Step 6: Final answer
    x = 91.75

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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.