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Finding the Fourth Proportional to 646.14, 891.90 and 397.88

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Solution

The fourth proportional to 646.14, 891.90 and 397.88 is: 549.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.14 : 891.90 = 397.88 : x
  2. Step 2: Convert to fraction form
    646.14/891.90 = 397.88/x
  3. Step 3: Cross multiply
    646.14x = 891.90 × 397.88
  4. Step 4: Simplify right side
    646.14x = 354,869.17
  5. Step 5: Solve for x
    x = 354,869.17/646.14
  6. Step 6: Final answer
    x = 549.21

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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.