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Finding the Fourth Proportional to 91.50, 125.07 and 87.72

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Solution

The fourth proportional to 91.50, 125.07 and 87.72 is: 119.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.50 : 125.07 = 87.72 : x
  2. Step 2: Convert to fraction form
    91.50/125.07 = 87.72/x
  3. Step 3: Cross multiply
    91.50x = 125.07 × 87.72
  4. Step 4: Simplify right side
    91.50x = 10,971.14
  5. Step 5: Solve for x
    x = 10,971.14/91.50
  6. Step 6: Final answer
    x = 119.90

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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.