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Finding the Fourth Proportional to 80.61, 111.17 and 65.06

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Solution

The fourth proportional to 80.61, 111.17 and 65.06 is: 89.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.61 : 111.17 = 65.06 : x
  2. Step 2: Convert to fraction form
    80.61/111.17 = 65.06/x
  3. Step 3: Cross multiply
    80.61x = 111.17 × 65.06
  4. Step 4: Simplify right side
    80.61x = 7,232.26
  5. Step 5: Solve for x
    x = 7,232.26/80.61
  6. Step 6: Final answer
    x = 89.72

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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.