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Finding the Fourth Proportional to 127.19, 190.61 and 81.51

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Solution

The fourth proportional to 127.19, 190.61 and 81.51 is: 122.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.19 : 190.61 = 81.51 : x
  2. Step 2: Convert to fraction form
    127.19/190.61 = 81.51/x
  3. Step 3: Cross multiply
    127.19x = 190.61 × 81.51
  4. Step 4: Simplify right side
    127.19x = 15,536.21
  5. Step 5: Solve for x
    x = 15,536.21/127.19
  6. Step 6: Final answer
    x = 122.15

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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.