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Finding the Fourth Proportional to 91.36, 126.71 and 90.28

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Solution

The fourth proportional to 91.36, 126.71 and 90.28 is: 125.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.36 : 126.71 = 90.28 : x
  2. Step 2: Convert to fraction form
    91.36/126.71 = 90.28/x
  3. Step 3: Cross multiply
    91.36x = 126.71 × 90.28
  4. Step 4: Simplify right side
    91.36x = 11,439.38
  5. Step 5: Solve for x
    x = 11,439.38/91.36
  6. Step 6: Final answer
    x = 125.21

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.