the table below gives the probability density of grades for a particular class.\n| grade | a | b | c | d | f…

the table below gives the probability density of grades for a particular class.\n| grade | a | b | c | d | f |\n| probability | 0.22 | 0.29 | 0.27 | 0.15 | 0.07 |\nif a student is selected at random, what is the probability that their grade is a b or c?\np = ?

the table below gives the probability density of grades for a particular class.\n| grade | a | b | c | d | f |\n| probability | 0.22 | 0.29 | 0.27 | 0.15 | 0.07 |\nif a student is selected at random, what is the probability that their grade is a b or c?\np = ?

Answer

Answer:

0.56

Explanation:

Step1: Identify relevant probabilities

The probability of getting a B is $P(B)=0.29$ and the probability of getting a C is $P(C)=0.27$.

Step2: Use addition rule for mutually - exclusive events

Since a student can't get a B and a C at the same time (mutually - exclusive events), $P(B\ or\ C)=P(B)+P(C)$. $P(B)+P(C)=0.29 + 0.27=0.56$