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Finding the Fourth Proportional to 77.25, 115.75 and 57.90

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Solution

The fourth proportional to 77.25, 115.75 and 57.90 is: 86.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.25 : 115.75 = 57.90 : x
  2. Step 2: Convert to fraction form
    77.25/115.75 = 57.90/x
  3. Step 3: Cross multiply
    77.25x = 115.75 × 57.90
  4. Step 4: Simplify right side
    77.25x = 6,701.93
  5. Step 5: Solve for x
    x = 6,701.93/77.25
  6. Step 6: Final answer
    x = 86.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.