Question

standardized tests for certain subjects, given to high school students, are scored on a scale of 1 to 5. let x represent the score on a randomly selected exam. the distribution of scores for one subjects standardized test is given in the table. what is the probability of earning a score lower than 3? 0.20 0.26 0.38 0.64

Explanation:

Step1: Identify scores lower than 3

Scores lower than 3 are 1 and 2.

Step2: Sum their probabilities

The probability of score 1 is \(P(X = 1)=0.18\), and the probability of score 2 is \(P(X = 2)=0.20\).
The sum is \(P(X<3)=P(X = 1)+P(X = 2)\)
\(P(X<3)=0.18 + 0.20\)
\(P(X<3)=0.38\)

Answer:

0.38