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Finding the Fourth Proportional to 78.31, 118.06 and 77.29

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Solution

The fourth proportional to 78.31, 118.06 and 77.29 is: 116.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.31 : 118.06 = 77.29 : x
  2. Step 2: Convert to fraction form
    78.31/118.06 = 77.29/x
  3. Step 3: Cross multiply
    78.31x = 118.06 × 77.29
  4. Step 4: Simplify right side
    78.31x = 9,124.61
  5. Step 5: Solve for x
    x = 9,124.61/78.31
  6. Step 6: Final answer
    x = 116.52

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.