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Finding the Fourth Proportional to 681.72, 940.79 and 386.99

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Solution

The fourth proportional to 681.72, 940.79 and 386.99 is: 534.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.72 : 940.79 = 386.99 : x
  2. Step 2: Convert to fraction form
    681.72/940.79 = 386.99/x
  3. Step 3: Cross multiply
    681.72x = 940.79 × 386.99
  4. Step 4: Simplify right side
    681.72x = 364,069.68
  5. Step 5: Solve for x
    x = 364,069.68/681.72
  6. Step 6: Final answer
    x = 534.05

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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.