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Finding the Fourth Proportional to 285.78, 393.15 and 238.22

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Solution

The fourth proportional to 285.78, 393.15 and 238.22 is: 327.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.78 : 393.15 = 238.22 : x
  2. Step 2: Convert to fraction form
    285.78/393.15 = 238.22/x
  3. Step 3: Cross multiply
    285.78x = 393.15 × 238.22
  4. Step 4: Simplify right side
    285.78x = 93,655.85
  5. Step 5: Solve for x
    x = 93,655.85/285.78
  6. Step 6: Final answer
    x = 327.72

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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.