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Finding the Fourth Proportional to 68.31, 94.28 and 39.21

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Solution

The fourth proportional to 68.31, 94.28 and 39.21 is: 54.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.31 : 94.28 = 39.21 : x
  2. Step 2: Convert to fraction form
    68.31/94.28 = 39.21/x
  3. Step 3: Cross multiply
    68.31x = 94.28 × 39.21
  4. Step 4: Simplify right side
    68.31x = 3,696.72
  5. Step 5: Solve for x
    x = 3,696.72/68.31
  6. Step 6: Final answer
    x = 54.12

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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.