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Finding the Fourth Proportional to 78.31, 116.91 and 68.06

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Solution

The fourth proportional to 78.31, 116.91 and 68.06 is: 101.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.31 : 116.91 = 68.06 : x
  2. Step 2: Convert to fraction form
    78.31/116.91 = 68.06/x
  3. Step 3: Cross multiply
    78.31x = 116.91 × 68.06
  4. Step 4: Simplify right side
    78.31x = 7,957.19
  5. Step 5: Solve for x
    x = 7,957.19/78.31
  6. Step 6: Final answer
    x = 101.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.