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Finding the Fourth Proportional to 216.45, 298.71 and 129.15

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Solution

The fourth proportional to 216.45, 298.71 and 129.15 is: 178.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.45 : 298.71 = 129.15 : x
  2. Step 2: Convert to fraction form
    216.45/298.71 = 129.15/x
  3. Step 3: Cross multiply
    216.45x = 298.71 × 129.15
  4. Step 4: Simplify right side
    216.45x = 38,578.40
  5. Step 5: Solve for x
    x = 38,578.40/216.45
  6. Step 6: Final answer
    x = 178.23

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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.