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Finding the Fourth Proportional to 147.81, 220.57 and 128.37

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Solution

The fourth proportional to 147.81, 220.57 and 128.37 is: 191.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.81 : 220.57 = 128.37 : x
  2. Step 2: Convert to fraction form
    147.81/220.57 = 128.37/x
  3. Step 3: Cross multiply
    147.81x = 220.57 × 128.37
  4. Step 4: Simplify right side
    147.81x = 28,314.57
  5. Step 5: Solve for x
    x = 28,314.57/147.81
  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.