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Finding the Fourth Proportional to 66.57, 99.79 and 54.39

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Solution

The fourth proportional to 66.57, 99.79 and 54.39 is: 81.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.57 : 99.79 = 54.39 : x
  2. Step 2: Convert to fraction form
    66.57/99.79 = 54.39/x
  3. Step 3: Cross multiply
    66.57x = 99.79 × 54.39
  4. Step 4: Simplify right side
    66.57x = 5,427.58
  5. Step 5: Solve for x
    x = 5,427.58/66.57
  6. Step 6: Final answer
    x = 81.53

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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.