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Finding the Fourth Proportional to 151.72, 209.38 and 91.91

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Solution

The fourth proportional to 151.72, 209.38 and 91.91 is: 126.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.72 : 209.38 = 91.91 : x
  2. Step 2: Convert to fraction form
    151.72/209.38 = 91.91/x
  3. Step 3: Cross multiply
    151.72x = 209.38 × 91.91
  4. Step 4: Simplify right side
    151.72x = 19,244.12
  5. Step 5: Solve for x
    x = 19,244.12/151.72
  6. Step 6: Final answer
    x = 126.84

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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.