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Finding the Fourth Proportional to 91.45, 125.28 and 87.98

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Solution

The fourth proportional to 91.45, 125.28 and 87.98 is: 120.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.45 : 125.28 = 87.98 : x
  2. Step 2: Convert to fraction form
    91.45/125.28 = 87.98/x
  3. Step 3: Cross multiply
    91.45x = 125.28 × 87.98
  4. Step 4: Simplify right side
    91.45x = 11,022.13
  5. Step 5: Solve for x
    x = 11,022.13/91.45
  6. Step 6: Final answer
    x = 120.53

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.