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Finding the Fourth Proportional to 91.69, 137.28 and 71.38

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Solution

The fourth proportional to 91.69, 137.28 and 71.38 is: 106.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.69 : 137.28 = 71.38 : x
  2. Step 2: Convert to fraction form
    91.69/137.28 = 71.38/x
  3. Step 3: Cross multiply
    91.69x = 137.28 × 71.38
  4. Step 4: Simplify right side
    91.69x = 9,799.05
  5. Step 5: Solve for x
    x = 9,799.05/91.69
  6. Step 6: Final answer
    x = 106.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.