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Finding the Fourth Proportional to 137.90, 190.40 and 91.28

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Solution

The fourth proportional to 137.90, 190.40 and 91.28 is: 126.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.90 : 190.40 = 91.28 : x
  2. Step 2: Convert to fraction form
    137.90/190.40 = 91.28/x
  3. Step 3: Cross multiply
    137.90x = 190.40 × 91.28
  4. Step 4: Simplify right side
    137.90x = 17,379.17
  5. Step 5: Solve for x
    x = 17,379.17/137.90
  6. Step 6: Final answer
    x = 126.03

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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.