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Finding the Fourth Proportional to 646.90, 892.79 and 398.23

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Solution

The fourth proportional to 646.90, 892.79 and 398.23 is: 549.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.90 : 892.79 = 398.23 : x
  2. Step 2: Convert to fraction form
    646.90/892.79 = 398.23/x
  3. Step 3: Cross multiply
    646.90x = 892.79 × 398.23
  4. Step 4: Simplify right side
    646.90x = 355,535.76
  5. Step 5: Solve for x
    x = 355,535.76/646.90
  6. Step 6: Final answer
    x = 549.60

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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.