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Finding the Fourth Proportional to 129.48, 193.40 and 128.81

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Solution

The fourth proportional to 129.48, 193.40 and 128.81 is: 192.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.48 : 193.40 = 128.81 : x
  2. Step 2: Convert to fraction form
    129.48/193.40 = 128.81/x
  3. Step 3: Cross multiply
    129.48x = 193.40 × 128.81
  4. Step 4: Simplify right side
    129.48x = 24,910.24
  5. Step 5: Solve for x
    x = 24,910.24/129.48
  6. Step 6: Final answer
    x = 192.39

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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.