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Finding the Fourth Proportional to 80.64, 111.31 and 51.57

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Solution

The fourth proportional to 80.64, 111.31 and 51.57 is: 71.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.64 : 111.31 = 51.57 : x
  2. Step 2: Convert to fraction form
    80.64/111.31 = 51.57/x
  3. Step 3: Cross multiply
    80.64x = 111.31 × 51.57
  4. Step 4: Simplify right side
    80.64x = 5,740.26
  5. Step 5: Solve for x
    x = 5,740.26/80.64
  6. Step 6: Final answer
    x = 71.18

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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.