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Finding the Fourth Proportional to 238.41, 328.95 and 138.78

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Solution

The fourth proportional to 238.41, 328.95 and 138.78 is: 191.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    238.41 : 328.95 = 138.78 : x
  2. Step 2: Convert to fraction form
    238.41/328.95 = 138.78/x
  3. Step 3: Cross multiply
    238.41x = 328.95 × 138.78
  4. Step 4: Simplify right side
    238.41x = 45,651.68
  5. Step 5: Solve for x
    x = 45,651.68/238.41
  6. Step 6: Final answer
    x = 191.48

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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.