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Finding the Fourth Proportional to 128.30, 193.28 and 121.94

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Solution

The fourth proportional to 128.30, 193.28 and 121.94 is: 183.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.30 : 193.28 = 121.94 : x
  2. Step 2: Convert to fraction form
    128.30/193.28 = 121.94/x
  3. Step 3: Cross multiply
    128.30x = 193.28 × 121.94
  4. Step 4: Simplify right side
    128.30x = 23,567.90
  5. Step 5: Solve for x
    x = 23,567.90/128.30
  6. Step 6: Final answer
    x = 183.69

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.