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Finding the Fourth Proportional to 91.45, 126.30 and 79.12

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Solution

The fourth proportional to 91.45, 126.30 and 79.12 is: 109.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.45 : 126.30 = 79.12 : x
  2. Step 2: Convert to fraction form
    91.45/126.30 = 79.12/x
  3. Step 3: Cross multiply
    91.45x = 126.30 × 79.12
  4. Step 4: Simplify right side
    91.45x = 9,992.86
  5. Step 5: Solve for x
    x = 9,992.86/91.45
  6. Step 6: Final answer
    x = 109.27

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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.