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Finding the Fourth Proportional to 392.80, 541.68 and 305.44

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Solution

The fourth proportional to 392.80, 541.68 and 305.44 is: 421.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.80 : 541.68 = 305.44 : x
  2. Step 2: Convert to fraction form
    392.80/541.68 = 305.44/x
  3. Step 3: Cross multiply
    392.80x = 541.68 × 305.44
  4. Step 4: Simplify right side
    392.80x = 165,450.74
  5. Step 5: Solve for x
    x = 165,450.74/392.80
  6. Step 6: Final answer
    x = 421.21

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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.