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Finding the Fourth Proportional to 393.85, 543.49 and 219.20

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Solution

The fourth proportional to 393.85, 543.49 and 219.20 is: 302.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.85 : 543.49 = 219.20 : x
  2. Step 2: Convert to fraction form
    393.85/543.49 = 219.20/x
  3. Step 3: Cross multiply
    393.85x = 543.49 × 219.20
  4. Step 4: Simplify right side
    393.85x = 119,133.01
  5. Step 5: Solve for x
    x = 119,133.01/393.85
  6. Step 6: Final answer
    x = 302.48

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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.