Question

the table below gives the probability density of grades for a particular class. if a student is selected at random, what is the probability that their grade is a d or f? p = ?

Explanation:

Step1: Identify relevant probabilities

The probability of grade D is \(0.15\), and the probability of grade F is \(0.07\).

Step2: Apply addition rule for mutually - exclusive events

Since a grade cannot be both D and F simultaneously (mutually - exclusive), use \(P(D\cup F)=P(D)+P(F)\).
So, \(P(D\cup F)=0.15 + 0.07\).

Step3: Calculate the sum

\(0.15+0.07 = 0.22\).

Answer:

\(0.22\)