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Finding the Fourth Proportional to 91.39, 126.02 and 79.71

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Solution

The fourth proportional to 91.39, 126.02 and 79.71 is: 109.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.39 : 126.02 = 79.71 : x
  2. Step 2: Convert to fraction form
    91.39/126.02 = 79.71/x
  3. Step 3: Cross multiply
    91.39x = 126.02 × 79.71
  4. Step 4: Simplify right side
    91.39x = 10,045.04
  5. Step 5: Solve for x
    x = 10,045.04/91.39
  6. Step 6: Final answer
    x = 109.91

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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.