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Finding the Fourth Proportional to 79.62, 118.69 and 78.71

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Solution

The fourth proportional to 79.62, 118.69 and 78.71 is: 117.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.62 : 118.69 = 78.71 : x
  2. Step 2: Convert to fraction form
    79.62/118.69 = 78.71/x
  3. Step 3: Cross multiply
    79.62x = 118.69 × 78.71
  4. Step 4: Simplify right side
    79.62x = 9,342.02
  5. Step 5: Solve for x
    x = 9,342.02/79.62
  6. Step 6: Final answer
    x = 117.33

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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.