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Finding the Fourth Proportional to 680.63, 1,020.31 and 620.51

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Solution

The fourth proportional to 680.63, 1,020.31 and 620.51 is: 930.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.63 : 1,020.31 = 620.51 : x
  2. Step 2: Convert to fraction form
    680.63/1,020.31 = 620.51/x
  3. Step 3: Cross multiply
    680.63x = 1,020.31 × 620.51
  4. Step 4: Simplify right side
    680.63x = 633,105.91
  5. Step 5: Solve for x
    x = 633,105.91/680.63
  6. Step 6: Final answer
    x = 930.18

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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.