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Finding the Fourth Proportional to 681.78, 940.65 and 419.70

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Solution

The fourth proportional to 681.78, 940.65 and 419.70 is: 579.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.78 : 940.65 = 419.70 : x
  2. Step 2: Convert to fraction form
    681.78/940.65 = 419.70/x
  3. Step 3: Cross multiply
    681.78x = 940.65 × 419.70
  4. Step 4: Simplify right side
    681.78x = 394,790.81
  5. Step 5: Solve for x
    x = 394,790.81/681.78
  6. Step 6: Final answer
    x = 579.06

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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.