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Finding the Fourth Proportional to 86.88, 130.20 and 76.56

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Solution

The fourth proportional to 86.88, 130.20 and 76.56 is: 114.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.88 : 130.20 = 76.56 : x
  2. Step 2: Convert to fraction form
    86.88/130.20 = 76.56/x
  3. Step 3: Cross multiply
    86.88x = 130.20 × 76.56
  4. Step 4: Simplify right side
    86.88x = 9,968.11
  5. Step 5: Solve for x
    x = 9,968.11/86.88
  6. Step 6: Final answer
    x = 114.73

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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.