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Finding the Fourth Proportional to 681.48, 1,021.15 and 388.62

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Solution

The fourth proportional to 681.48, 1,021.15 and 388.62 is: 582.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.48 : 1,021.15 = 388.62 : x
  2. Step 2: Convert to fraction form
    681.48/1,021.15 = 388.62/x
  3. Step 3: Cross multiply
    681.48x = 1,021.15 × 388.62
  4. Step 4: Simplify right side
    681.48x = 396,839.31
  5. Step 5: Solve for x
    x = 396,839.31/681.48
  6. Step 6: Final answer
    x = 582.32

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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.