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Finding the Fourth Proportional to 66.08, 91.17 and 39.85

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Solution

The fourth proportional to 66.08, 91.17 and 39.85 is: 54.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.08 : 91.17 = 39.85 : x
  2. Step 2: Convert to fraction form
    66.08/91.17 = 39.85/x
  3. Step 3: Cross multiply
    66.08x = 91.17 × 39.85
  4. Step 4: Simplify right side
    66.08x = 3,632.67
  5. Step 5: Solve for x
    x = 3,632.67/66.08
  6. Step 6: Final answer
    x = 54.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.