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Finding the Fourth Proportional to 285.12, 393.12 and 219.78

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Solution

The fourth proportional to 285.12, 393.12 and 219.78 is: 303.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.12 : 393.12 = 219.78 : x
  2. Step 2: Convert to fraction form
    285.12/393.12 = 219.78/x
  3. Step 3: Cross multiply
    285.12x = 393.12 × 219.78
  4. Step 4: Simplify right side
    285.12x = 86,399.91
  5. Step 5: Solve for x
    x = 86,399.91/285.12
  6. Step 6: Final answer
    x = 303.03

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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.