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Finding the Fourth Proportional to 680.63, 1,020.47 and 388.22

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Solution

The fourth proportional to 680.63, 1,020.47 and 388.22 is: 582.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.63 : 1,020.47 = 388.22 : x
  2. Step 2: Convert to fraction form
    680.63/1,020.47 = 388.22/x
  3. Step 3: Cross multiply
    680.63x = 1,020.47 × 388.22
  4. Step 4: Simplify right side
    680.63x = 396,159.82
  5. Step 5: Solve for x
    x = 396,159.82/680.63
  6. Step 6: Final answer
    x = 582.05

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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.