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Finding the Fourth Proportional to 646.86, 892.40 and 397.98

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Solution

The fourth proportional to 646.86, 892.40 and 397.98 is: 549.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.86 : 892.40 = 397.98 : x
  2. Step 2: Convert to fraction form
    646.86/892.40 = 397.98/x
  3. Step 3: Cross multiply
    646.86x = 892.40 × 397.98
  4. Step 4: Simplify right side
    646.86x = 355,157.35
  5. Step 5: Solve for x
    x = 355,157.35/646.86
  6. Step 6: Final answer
    x = 549.05

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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.