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Finding the Fourth Proportional to 646.31, 891.86 and 397.64

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Solution

The fourth proportional to 646.31, 891.86 and 397.64 is: 548.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.31 : 891.86 = 397.64 : x
  2. Step 2: Convert to fraction form
    646.31/891.86 = 397.64/x
  3. Step 3: Cross multiply
    646.31x = 891.86 × 397.64
  4. Step 4: Simplify right side
    646.31x = 354,632.76
  5. Step 5: Solve for x
    x = 354,632.76/646.31
  6. Step 6: Final answer
    x = 548.71

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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.