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Finding the Fourth Proportional to 641.75, 885.83 and 399.41

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Solution

The fourth proportional to 641.75, 885.83 and 399.41 is: 551.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.75 : 885.83 = 399.41 : x
  2. Step 2: Convert to fraction form
    641.75/885.83 = 399.41/x
  3. Step 3: Cross multiply
    641.75x = 885.83 × 399.41
  4. Step 4: Simplify right side
    641.75x = 353,804.93
  5. Step 5: Solve for x
    x = 353,804.93/641.75
  6. Step 6: Final answer
    x = 551.32

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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.