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Finding the Fourth Proportional to 681.75, 940.80 and 387.05

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Solution

The fourth proportional to 681.75, 940.80 and 387.05 is: 534.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.75 : 940.80 = 387.05 : x
  2. Step 2: Convert to fraction form
    681.75/940.80 = 387.05/x
  3. Step 3: Cross multiply
    681.75x = 940.80 × 387.05
  4. Step 4: Simplify right side
    681.75x = 364,136.64
  5. Step 5: Solve for x
    x = 364,136.64/681.75
  6. Step 6: Final answer
    x = 534.12

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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.