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Finding the Fourth Proportional to 128.82, 193.18 and 79.99

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Solution

The fourth proportional to 128.82, 193.18 and 79.99 is: 119.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.82 : 193.18 = 79.99 : x
  2. Step 2: Convert to fraction form
    128.82/193.18 = 79.99/x
  3. Step 3: Cross multiply
    128.82x = 193.18 × 79.99
  4. Step 4: Simplify right side
    128.82x = 15,452.51
  5. Step 5: Solve for x
    x = 15,452.51/128.82
  6. Step 6: Final answer
    x = 119.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.