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Finding the Fourth Proportional to 210.78, 290.78 and 122.22

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Solution

The fourth proportional to 210.78, 290.78 and 122.22 is: 168.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.78 : 290.78 = 122.22 : x
  2. Step 2: Convert to fraction form
    210.78/290.78 = 122.22/x
  3. Step 3: Cross multiply
    210.78x = 290.78 × 122.22
  4. Step 4: Simplify right side
    210.78x = 35,539.13
  5. Step 5: Solve for x
    x = 35,539.13/210.78
  6. Step 6: Final answer
    x = 168.61

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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.