Answer :
To determine the probability that a randomly selected student got a B, we need to understand that the sum of all probabilities should equal 1. The given probabilities for grades A, C, D, and F are 0.43, 0.17, 0.05, and 0.04 respectively. We'll use these values to find the missing probability for grade B.
Here is your step-by-step solution:
1. Identify the given probabilities:
- Probability of getting an A (grade 4) = 0.43
- Probability of getting a C (grade 2) = 0.17
- Probability of getting a D (grade 1) = 0.05
- Probability of getting an F (grade 0) = 0.04
2. Sum the given probabilities:
[tex]\[ 0.43 (A) + 0.17 (C) + 0.05 (D) + 0.04 (F) = 0.69 \][/tex]
3. Calculate the missing probability for grade B (grade 3):
Since the total probability must equal 1, subtract the sum of the given probabilities from 1:
[tex]\[ 1 - 0.69 = 0.31 \][/tex]
Therefore, the probability that a randomly selected student got a B is [tex]\( \boxed{0.31} \)[/tex].
Here is your step-by-step solution:
1. Identify the given probabilities:
- Probability of getting an A (grade 4) = 0.43
- Probability of getting a C (grade 2) = 0.17
- Probability of getting a D (grade 1) = 0.05
- Probability of getting an F (grade 0) = 0.04
2. Sum the given probabilities:
[tex]\[ 0.43 (A) + 0.17 (C) + 0.05 (D) + 0.04 (F) = 0.69 \][/tex]
3. Calculate the missing probability for grade B (grade 3):
Since the total probability must equal 1, subtract the sum of the given probabilities from 1:
[tex]\[ 1 - 0.69 = 0.31 \][/tex]
Therefore, the probability that a randomly selected student got a B is [tex]\( \boxed{0.31} \)[/tex].