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Finding the Fourth Proportional to 160.81, 221.95 and 128.20

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Solution

The fourth proportional to 160.81, 221.95 and 128.20 is: 176.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    160.81 : 221.95 = 128.20 : x
  2. Step 2: Convert to fraction form
    160.81/221.95 = 128.20/x
  3. Step 3: Cross multiply
    160.81x = 221.95 × 128.20
  4. Step 4: Simplify right side
    160.81x = 28,453.99
  5. Step 5: Solve for x
    x = 28,453.99/160.81
  6. Step 6: Final answer
    x = 176.94

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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.