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Finding the Fourth Proportional to 486.64, 670.44 and 398.80

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Solution

The fourth proportional to 486.64, 670.44 and 398.80 is: 549.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.64 : 670.44 = 398.80 : x
  2. Step 2: Convert to fraction form
    486.64/670.44 = 398.80/x
  3. Step 3: Cross multiply
    486.64x = 670.44 × 398.80
  4. Step 4: Simplify right side
    486.64x = 267,371.47
  5. Step 5: Solve for x
    x = 267,371.47/486.64
  6. Step 6: Final answer
    x = 549.42

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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.