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Finding the Fourth Proportional to 165.21, 227.81 and 128.28

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Solution

The fourth proportional to 165.21, 227.81 and 128.28 is: 176.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    165.21 : 227.81 = 128.28 : x
  2. Step 2: Convert to fraction form
    165.21/227.81 = 128.28/x
  3. Step 3: Cross multiply
    165.21x = 227.81 × 128.28
  4. Step 4: Simplify right side
    165.21x = 29,224.64
  5. Step 5: Solve for x
    x = 29,224.64/165.21
  6. Step 6: Final answer
    x = 176.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.