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Finding the Fourth Proportional to 210.21, 290.12 and 122.87

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Solution

The fourth proportional to 210.21, 290.12 and 122.87 is: 169.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.21 : 290.12 = 122.87 : x
  2. Step 2: Convert to fraction form
    210.21/290.12 = 122.87/x
  3. Step 3: Cross multiply
    210.21x = 290.12 × 122.87
  4. Step 4: Simplify right side
    210.21x = 35,645.90
  5. Step 5: Solve for x
    x = 35,645.90/210.21
  6. Step 6: Final answer
    x = 169.57

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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.