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Finding the Fourth Proportional to 238.20, 328.78 and 139.98

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Solution

The fourth proportional to 238.20, 328.78 and 139.98 is: 193.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    238.20 : 328.78 = 139.98 : x
  2. Step 2: Convert to fraction form
    238.20/328.78 = 139.98/x
  3. Step 3: Cross multiply
    238.20x = 328.78 × 139.98
  4. Step 4: Simplify right side
    238.20x = 46,023.24
  5. Step 5: Solve for x
    x = 46,023.24/238.20
  6. Step 6: Final answer
    x = 193.22

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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.