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Finding the Fourth Proportional to 134.19, 199.80 and 128.66

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Solution

The fourth proportional to 134.19, 199.80 and 128.66 is: 191.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    134.19 : 199.80 = 128.66 : x
  2. Step 2: Convert to fraction form
    134.19/199.80 = 128.66/x
  3. Step 3: Cross multiply
    134.19x = 199.80 × 128.66
  4. Step 4: Simplify right side
    134.19x = 25,705.27
  5. Step 5: Solve for x
    x = 25,705.27/134.19
  6. Step 6: Final answer
    x = 191.56

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.