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Finding the Fourth Proportional to 238.78, 357.99 and 128.98

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Solution

The fourth proportional to 238.78, 357.99 and 128.98 is: 193.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    238.78 : 357.99 = 128.98 : x
  2. Step 2: Convert to fraction form
    238.78/357.99 = 128.98/x
  3. Step 3: Cross multiply
    238.78x = 357.99 × 128.98
  4. Step 4: Simplify right side
    238.78x = 46,173.55
  5. Step 5: Solve for x
    x = 46,173.55/238.78
  6. Step 6: Final answer
    x = 193.37

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.