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Finding the Fourth Proportional to 80.94, 111.78 and 64.66

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Solution

The fourth proportional to 80.94, 111.78 and 64.66 is: 89.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.94 : 111.78 = 64.66 : x
  2. Step 2: Convert to fraction form
    80.94/111.78 = 64.66/x
  3. Step 3: Cross multiply
    80.94x = 111.78 × 64.66
  4. Step 4: Simplify right side
    80.94x = 7,227.69
  5. Step 5: Solve for x
    x = 7,227.69/80.94
  6. Step 6: Final answer
    x = 89.30

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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.