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Finding the Fourth Proportional to 79.32, 118.13 and 77.80

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Solution

The fourth proportional to 79.32, 118.13 and 77.80 is: 115.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.32 : 118.13 = 77.80 : x
  2. Step 2: Convert to fraction form
    79.32/118.13 = 77.80/x
  3. Step 3: Cross multiply
    79.32x = 118.13 × 77.80
  4. Step 4: Simplify right side
    79.32x = 9,190.51
  5. Step 5: Solve for x
    x = 9,190.51/79.32
  6. Step 6: Final answer
    x = 115.87

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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.