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Finding the Fourth Proportional to 129.81, 178.32 and 123.23

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Solution

The fourth proportional to 129.81, 178.32 and 123.23 is: 169.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.81 : 178.32 = 123.23 : x
  2. Step 2: Convert to fraction form
    129.81/178.32 = 123.23/x
  3. Step 3: Cross multiply
    129.81x = 178.32 × 123.23
  4. Step 4: Simplify right side
    129.81x = 21,975.28
  5. Step 5: Solve for x
    x = 21,975.28/129.81
  6. Step 6: Final answer
    x = 169.28

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.