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Finding the Fourth Proportional to 641.55, 885.08 and 392.69

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Solution

The fourth proportional to 641.55, 885.08 and 392.69 is: 541.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.55 : 885.08 = 392.69 : x
  2. Step 2: Convert to fraction form
    641.55/885.08 = 392.69/x
  3. Step 3: Cross multiply
    641.55x = 885.08 × 392.69
  4. Step 4: Simplify right side
    641.55x = 347,555.68
  5. Step 5: Solve for x
    x = 347,555.68/641.55
  6. Step 6: Final answer
    x = 541.74

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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.