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Finding the Fourth Proportional to 86.88, 130.32 and 54.72

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Solution

The fourth proportional to 86.88, 130.32 and 54.72 is: 82.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.88 : 130.32 = 54.72 : x
  2. Step 2: Convert to fraction form
    86.88/130.32 = 54.72/x
  3. Step 3: Cross multiply
    86.88x = 130.32 × 54.72
  4. Step 4: Simplify right side
    86.88x = 7,131.11
  5. Step 5: Solve for x
    x = 7,131.11/86.88
  6. Step 6: Final answer
    x = 82.08

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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.