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Finding the Fourth Proportional to 681.78, 940.58 and 386.99

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Solution

The fourth proportional to 681.78, 940.58 and 386.99 is: 533.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.78 : 940.58 = 386.99 : x
  2. Step 2: Convert to fraction form
    681.78/940.58 = 386.99/x
  3. Step 3: Cross multiply
    681.78x = 940.58 × 386.99
  4. Step 4: Simplify right side
    681.78x = 363,998.69
  5. Step 5: Solve for x
    x = 363,998.69/681.78
  6. Step 6: Final answer
    x = 533.89

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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.