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Finding the Fourth Proportional to 128.69, 193.13 and 113.50

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Solution

The fourth proportional to 128.69, 193.13 and 113.50 is: 170.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.69 : 193.13 = 113.50 : x
  2. Step 2: Convert to fraction form
    128.69/193.13 = 113.50/x
  3. Step 3: Cross multiply
    128.69x = 193.13 × 113.50
  4. Step 4: Simplify right side
    128.69x = 21,918.72
  5. Step 5: Solve for x
    x = 21,918.72/128.69
  6. Step 6: Final answer
    x = 170.33

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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.