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Finding the Fourth Proportional to 80.70, 111.48 and 66.30

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Solution

The fourth proportional to 80.70, 111.48 and 66.30 is: 91.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.70 : 111.48 = 66.30 : x
  2. Step 2: Convert to fraction form
    80.70/111.48 = 66.30/x
  3. Step 3: Cross multiply
    80.70x = 111.48 × 66.30
  4. Step 4: Simplify right side
    80.70x = 7,391.12
  5. Step 5: Solve for x
    x = 7,391.12/80.70
  6. Step 6: Final answer
    x = 91.59

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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.