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Finding the Fourth Proportional to 210.06, 315.09 and 81.81

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Solution

The fourth proportional to 210.06, 315.09 and 81.81 is: 122.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.06 : 315.09 = 81.81 : x
  2. Step 2: Convert to fraction form
    210.06/315.09 = 81.81/x
  3. Step 3: Cross multiply
    210.06x = 315.09 × 81.81
  4. Step 4: Simplify right side
    210.06x = 25,777.51
  5. Step 5: Solve for x
    x = 25,777.51/210.06
  6. Step 6: Final answer
    x = 122.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.