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Finding the Fourth Proportional to 646.79, 892.42 and 398.12

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Solution

The fourth proportional to 646.79, 892.42 and 398.12 is: 549.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.79 : 892.42 = 398.12 : x
  2. Step 2: Convert to fraction form
    646.79/892.42 = 398.12/x
  3. Step 3: Cross multiply
    646.79x = 892.42 × 398.12
  4. Step 4: Simplify right side
    646.79x = 355,284.79
  5. Step 5: Solve for x
    x = 355,284.79/646.79
  6. Step 6: Final answer
    x = 549.31

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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.