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Finding the Fourth Proportional to 133.40, 199.67 and 128.61

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Solution

The fourth proportional to 133.40, 199.67 and 128.61 is: 192.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    133.40 : 199.67 = 128.61 : x
  2. Step 2: Convert to fraction form
    133.40/199.67 = 128.61/x
  3. Step 3: Cross multiply
    133.40x = 199.67 × 128.61
  4. Step 4: Simplify right side
    133.40x = 25,678.92
  5. Step 5: Solve for x
    x = 25,678.92/133.40
  6. Step 6: Final answer
    x = 192.50

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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.