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Finding the Fourth Proportional to 128.81, 193.30 and 67.99

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Solution

The fourth proportional to 128.81, 193.30 and 67.99 is: 102.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.81 : 193.30 = 67.99 : x
  2. Step 2: Convert to fraction form
    128.81/193.30 = 67.99/x
  3. Step 3: Cross multiply
    128.81x = 193.30 × 67.99
  4. Step 4: Simplify right side
    128.81x = 13,142.47
  5. Step 5: Solve for x
    x = 13,142.47/128.81
  6. Step 6: Final answer
    x = 102.03

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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.