$$ \text{Class Entropy} = - \frac{7}{11} \log_2 \frac{7}{11} - \frac{4}{11} \log_2 \frac{4}{11} $$

Since scientific calculator doesn't have a direct "log base 2" function, we'll use the change of base formula again:

$$ \log_2 x = \frac{\log_{10} x}{\log_{10} 2} $$

Updated Step-by-Step Calculation:

1. Calculate $- \frac{7}{11} \log_2 \frac{7}{11}$:

   1. First, divide $7$ by $11$:

      $$ \frac{7}{11} = 0.63636 $$

   2. Find $\log_{10} 0.63636$:

      $$ \log_{10} 0.63636 \approx -0.1959 $$

   3. Find $\log_{10} 2$:

      $$ \log_{10} 2 \approx 0.3010 $$

   4. Calculate $\log_2 \frac{7}{11}$:

      $$ \frac{-0.1959}{0.3010} \approx -0.6507 $$

   5. Multiply $\frac{7}{11}$ by $\log_2 \frac{7}{11}$:

      $$ \frac{7}{11} \times -0.6507 \approx -0.4140 $$

   6. Apply the negative sign:

      $$ -(-0.4140) = 0.4140 $$

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2. Calculate $- \frac{4}{11} \log_2 \frac{4}{11}$:

   1. Divide $4$ by $11$:

      $$ \frac{4}{11} = 0.36363 $$

   2. Find $\log_{10} 0.36363$:

      $$ \log_{10} 0.36363 \approx -0.4393 $$

   3. Calculate $\log_2 \frac{4}{11}$:

      $$ \frac{-0.4393}{0.3010} \approx -1.4598 $$

   4. Multiply $\frac{4}{11}$ by $\log_2 \frac{4}{11}$:

      $$ \frac{4}{11} \times -1.4598 \approx -0.5308 $$

   5. Apply the negative sign:

      $$ -(-0.5308) = 0.5308 $$

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3. Add the results together:

   1. Add $0.4140$ and $0.5308$:

      $$ 0.4140 + 0.5308 = 0.9448 $$

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4. Final Answer:

   1. Class Entropy ≈ 0.9448