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Finding the Fourth Proportional to 681.64, 940.28 and 401.78

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Solution

The fourth proportional to 681.64, 940.28 and 401.78 is: 554.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.64 : 940.28 = 401.78 : x
  2. Step 2: Convert to fraction form
    681.64/940.28 = 401.78/x
  3. Step 3: Cross multiply
    681.64x = 940.28 × 401.78
  4. Step 4: Simplify right side
    681.64x = 377,786.04
  5. Step 5: Solve for x
    x = 377,786.04/681.64
  6. Step 6: Final answer
    x = 554.23

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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.