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Finding the Fourth Proportional to 646.57, 891.97 and 397.90

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Solution

The fourth proportional to 646.57, 891.97 and 397.90 is: 548.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.57 : 891.97 = 397.90 : x
  2. Step 2: Convert to fraction form
    646.57/891.97 = 397.90/x
  3. Step 3: Cross multiply
    646.57x = 891.97 × 397.90
  4. Step 4: Simplify right side
    646.57x = 354,914.86
  5. Step 5: Solve for x
    x = 354,914.86/646.57
  6. Step 6: Final answer
    x = 548.92

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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.