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Finding the Fourth Proportional to 128.33, 192.38 and 87.69

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Solution

The fourth proportional to 128.33, 192.38 and 87.69 is: 131.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.33 : 192.38 = 87.69 : x
  2. Step 2: Convert to fraction form
    128.33/192.38 = 87.69/x
  3. Step 3: Cross multiply
    128.33x = 192.38 × 87.69
  4. Step 4: Simplify right side
    128.33x = 16,869.36
  5. Step 5: Solve for x
    x = 16,869.36/128.33
  6. Step 6: Final answer
    x = 131.46

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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.