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Finding the Fourth Proportional to 79.69, 120.13 and 78.48

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Solution

The fourth proportional to 79.69, 120.13 and 78.48 is: 118.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.69 : 120.13 = 78.48 : x
  2. Step 2: Convert to fraction form
    79.69/120.13 = 78.48/x
  3. Step 3: Cross multiply
    79.69x = 120.13 × 78.48
  4. Step 4: Simplify right side
    79.69x = 9,427.80
  5. Step 5: Solve for x
    x = 9,427.80/79.69
  6. Step 6: Final answer
    x = 118.31

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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.