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Finding the Fourth Proportional to 213.09, 319.59 and 91.41

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Solution

The fourth proportional to 213.09, 319.59 and 91.41 is: 137.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.09 : 319.59 = 91.41 : x
  2. Step 2: Convert to fraction form
    213.09/319.59 = 91.41/x
  3. Step 3: Cross multiply
    213.09x = 319.59 × 91.41
  4. Step 4: Simplify right side
    213.09x = 29,213.72
  5. Step 5: Solve for x
    x = 29,213.72/213.09
  6. Step 6: Final answer
    x = 137.10

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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.