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Finding the Fourth Proportional to 688.40, 1,032.26 and 219.81

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Solution

The fourth proportional to 688.40, 1,032.26 and 219.81 is: 329.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.40 : 1,032.26 = 219.81 : x
  2. Step 2: Convert to fraction form
    688.40/1,032.26 = 219.81/x
  3. Step 3: Cross multiply
    688.40x = 1,032.26 × 219.81
  4. Step 4: Simplify right side
    688.40x = 226,901.43
  5. Step 5: Solve for x
    x = 226,901.43/688.40
  6. Step 6: Final answer
    x = 329.61

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.