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Finding the Fourth Proportional to 681.36, 940.31 and 386.61

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Solution

The fourth proportional to 681.36, 940.31 and 386.61 is: 533.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.36 : 940.31 = 386.61 : x
  2. Step 2: Convert to fraction form
    681.36/940.31 = 386.61/x
  3. Step 3: Cross multiply
    681.36x = 940.31 × 386.61
  4. Step 4: Simplify right side
    681.36x = 363,533.25
  5. Step 5: Solve for x
    x = 363,533.25/681.36
  6. Step 6: Final answer
    x = 533.54

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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.