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Finding the Fourth Proportional to 91.80, 125.87 and 90.54

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Solution

The fourth proportional to 91.80, 125.87 and 90.54 is: 124.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.80 : 125.87 = 90.54 : x
  2. Step 2: Convert to fraction form
    91.80/125.87 = 90.54/x
  3. Step 3: Cross multiply
    91.80x = 125.87 × 90.54
  4. Step 4: Simplify right side
    91.80x = 11,395.82
  5. Step 5: Solve for x
    x = 11,395.82/91.80
  6. Step 6: Final answer
    x = 124.14

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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.