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Finding the Fourth Proportional to 91.06, 137.13 and 79.78

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Solution

The fourth proportional to 91.06, 137.13 and 79.78 is: 120.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.06 : 137.13 = 79.78 : x
  2. Step 2: Convert to fraction form
    91.06/137.13 = 79.78/x
  3. Step 3: Cross multiply
    91.06x = 137.13 × 79.78
  4. Step 4: Simplify right side
    91.06x = 10,940.23
  5. Step 5: Solve for x
    x = 10,940.23/91.06
  6. Step 6: Final answer
    x = 120.14

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.