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Finding the Fourth Proportional to 108.35, 163.15 and 78.12

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Solution

The fourth proportional to 108.35, 163.15 and 78.12 is: 117.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.35 : 163.15 = 78.12 : x
  2. Step 2: Convert to fraction form
    108.35/163.15 = 78.12/x
  3. Step 3: Cross multiply
    108.35x = 163.15 × 78.12
  4. Step 4: Simplify right side
    108.35x = 12,745.28
  5. Step 5: Solve for x
    x = 12,745.28/108.35
  6. Step 6: Final answer
    x = 117.63

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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.