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Finding the Fourth Proportional to 216.81, 299.03 and 129.40

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Solution

The fourth proportional to 216.81, 299.03 and 129.40 is: 178.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.81 : 299.03 = 129.40 : x
  2. Step 2: Convert to fraction form
    216.81/299.03 = 129.40/x
  3. Step 3: Cross multiply
    216.81x = 299.03 × 129.40
  4. Step 4: Simplify right side
    216.81x = 38,693.09
  5. Step 5: Solve for x
    x = 38,693.09/216.81
  6. Step 6: Final answer
    x = 178.47

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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.