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Finding the Fourth Proportional to 91.70, 127.43 and 90.75

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Solution

The fourth proportional to 91.70, 127.43 and 90.75 is: 126.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.70 : 127.43 = 90.75 : x
  2. Step 2: Convert to fraction form
    91.70/127.43 = 90.75/x
  3. Step 3: Cross multiply
    91.70x = 127.43 × 90.75
  4. Step 4: Simplify right side
    91.70x = 11,564.27
  5. Step 5: Solve for x
    x = 11,564.27/91.70
  6. Step 6: Final answer
    x = 126.11

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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.