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Finding the Fourth Proportional to 285.42, 393.89 and 154.43

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Solution

The fourth proportional to 285.42, 393.89 and 154.43 is: 213.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.42 : 393.89 = 154.43 : x
  2. Step 2: Convert to fraction form
    285.42/393.89 = 154.43/x
  3. Step 3: Cross multiply
    285.42x = 393.89 × 154.43
  4. Step 4: Simplify right side
    285.42x = 60,828.84
  5. Step 5: Solve for x
    x = 60,828.84/285.42
  6. Step 6: Final answer
    x = 213.12

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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.