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Finding the Fourth Proportional to 210.71, 290.79 and 122.15

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Solution

The fourth proportional to 210.71, 290.79 and 122.15 is: 168.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.71 : 290.79 = 122.15 : x
  2. Step 2: Convert to fraction form
    210.71/290.79 = 122.15/x
  3. Step 3: Cross multiply
    210.71x = 290.79 × 122.15
  4. Step 4: Simplify right side
    210.71x = 35,520.73
  5. Step 5: Solve for x
    x = 35,520.73/210.71
  6. Step 6: Final answer
    x = 168.57

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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.