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Finding the Fourth Proportional to 79.29, 118.26 and 78.21

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Solution

The fourth proportional to 79.29, 118.26 and 78.21 is: 116.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.29 : 118.26 = 78.21 : x
  2. Step 2: Convert to fraction form
    79.29/118.26 = 78.21/x
  3. Step 3: Cross multiply
    79.29x = 118.26 × 78.21
  4. Step 4: Simplify right side
    79.29x = 9,249.11
  5. Step 5: Solve for x
    x = 9,249.11/79.29
  6. Step 6: Final answer
    x = 116.65

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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.