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Finding the Fourth Proportional to 128.36, 192.53 and 87.49

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Solution

The fourth proportional to 128.36, 192.53 and 87.49 is: 131.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.36 : 192.53 = 87.49 : x
  2. Step 2: Convert to fraction form
    128.36/192.53 = 87.49/x
  3. Step 3: Cross multiply
    128.36x = 192.53 × 87.49
  4. Step 4: Simplify right side
    128.36x = 16,843.49
  5. Step 5: Solve for x
    x = 16,843.49/128.36
  6. Step 6: Final answer
    x = 131.23

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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.