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Finding the Fourth Proportional to 66.64, 91.90 and 58.66

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Solution

The fourth proportional to 66.64, 91.90 and 58.66 is: 80.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.64 : 91.90 = 58.66 : x
  2. Step 2: Convert to fraction form
    66.64/91.90 = 58.66/x
  3. Step 3: Cross multiply
    66.64x = 91.90 × 58.66
  4. Step 4: Simplify right side
    66.64x = 5,390.85
  5. Step 5: Solve for x
    x = 5,390.85/66.64
  6. Step 6: Final answer
    x = 80.90

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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.