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Finding the Fourth Proportional to 85.05, 117.32 and 68.72

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Solution

The fourth proportional to 85.05, 117.32 and 68.72 is: 94.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.05 : 117.32 = 68.72 : x
  2. Step 2: Convert to fraction form
    85.05/117.32 = 68.72/x
  3. Step 3: Cross multiply
    85.05x = 117.32 × 68.72
  4. Step 4: Simplify right side
    85.05x = 8,061.30
  5. Step 5: Solve for x
    x = 8,061.30/85.05
  6. Step 6: Final answer
    x = 94.78

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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.