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Finding the Fourth Proportional to 216.86, 299.21 and 129.51

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Solution

The fourth proportional to 216.86, 299.21 and 129.51 is: 178.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.86 : 299.21 = 129.51 : x
  2. Step 2: Convert to fraction form
    216.86/299.21 = 129.51/x
  3. Step 3: Cross multiply
    216.86x = 299.21 × 129.51
  4. Step 4: Simplify right side
    216.86x = 38,750.04
  5. Step 5: Solve for x
    x = 38,750.04/216.86
  6. Step 6: Final answer
    x = 178.69

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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.