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Finding the Fourth Proportional to 689.22, 951.05 and 390.44

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Solution

The fourth proportional to 689.22, 951.05 and 390.44 is: 538.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.22 : 951.05 = 390.44 : x
  2. Step 2: Convert to fraction form
    689.22/951.05 = 390.44/x
  3. Step 3: Cross multiply
    689.22x = 951.05 × 390.44
  4. Step 4: Simplify right side
    689.22x = 371,321.25
  5. Step 5: Solve for x
    x = 371,321.25/689.22
  6. Step 6: Final answer
    x = 538.76

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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.