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Finding the Fourth Proportional to 161.71, 222.89 and 128.65

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Solution

The fourth proportional to 161.71, 222.89 and 128.65 is: 177.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.71 : 222.89 = 128.65 : x
  2. Step 2: Convert to fraction form
    161.71/222.89 = 128.65/x
  3. Step 3: Cross multiply
    161.71x = 222.89 × 128.65
  4. Step 4: Simplify right side
    161.71x = 28,673.68
  5. Step 5: Solve for x
    x = 28,673.68/161.71
  6. Step 6: Final answer
    x = 177.32

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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.