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Finding the Fourth Proportional to 285.19, 393.56 and 154.20

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Solution

The fourth proportional to 285.19, 393.56 and 154.20 is: 212.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.19 : 393.56 = 154.20 : x
  2. Step 2: Convert to fraction form
    285.19/393.56 = 154.20/x
  3. Step 3: Cross multiply
    285.19x = 393.56 × 154.20
  4. Step 4: Simplify right side
    285.19x = 60,685.28
  5. Step 5: Solve for x
    x = 60,685.28/285.19
  6. Step 6: Final answer
    x = 212.79

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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.