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Finding the Fourth Proportional to 408.40, 612.60 and 401.20

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Solution

The fourth proportional to 408.40, 612.60 and 401.20 is: 601.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.40 : 612.60 = 401.20 : x
  2. Step 2: Convert to fraction form
    408.40/612.60 = 401.20/x
  3. Step 3: Cross multiply
    408.40x = 612.60 × 401.20
  4. Step 4: Simplify right side
    408.40x = 245,775.12
  5. Step 5: Solve for x
    x = 245,775.12/408.40
  6. Step 6: Final answer
    x = 601.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.