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Finding the Fourth Proportional to 689.30, 951.22 and 390.54

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Solution

The fourth proportional to 689.30, 951.22 and 390.54 is: 538.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.30 : 951.22 = 390.54 : x
  2. Step 2: Convert to fraction form
    689.30/951.22 = 390.54/x
  3. Step 3: Cross multiply
    689.30x = 951.22 × 390.54
  4. Step 4: Simplify right side
    689.30x = 371,493.51
  5. Step 5: Solve for x
    x = 371,493.51/689.30
  6. Step 6: Final answer
    x = 538.94

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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.