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Finding the Fourth Proportional to 129.21, 178 and 119.79

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Solution

The fourth proportional to 129.21, 178 and 119.79 is: 165.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.21 : 178 = 119.79 : x
  2. Step 2: Convert to fraction form
    129.21/178 = 119.79/x
  3. Step 3: Cross multiply
    129.21x = 178 × 119.79
  4. Step 4: Simplify right side
    129.21x = 21,322.62
  5. Step 5: Solve for x
    x = 21,322.62/129.21
  6. Step 6: Final answer
    x = 165.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.