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Finding the Fourth Proportional to 79.77, 120.38 and 76.91

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Solution

The fourth proportional to 79.77, 120.38 and 76.91 is: 116.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.77 : 120.38 = 76.91 : x
  2. Step 2: Convert to fraction form
    79.77/120.38 = 76.91/x
  3. Step 3: Cross multiply
    79.77x = 120.38 × 76.91
  4. Step 4: Simplify right side
    79.77x = 9,258.04
  5. Step 5: Solve for x
    x = 9,258.04/79.77
  6. Step 6: Final answer
    x = 116.06

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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.