Question

Students at University X must be in one of the class ranks—freshman, sophomore, junior, or senior. At University X, 35% of the students are freshmen and 30% are sophomores. If a student is selected at random, the probability that her or she is either a junior or a senior is

Answer 1

Answer:

$P(Junior\ or\ Senior)=0.35$

Percentage of probability of junior or senior student is 35%.

Step-by-step explanation:

Given:

Freshmen = 35%

Sophomores = 30%

We need to find the the probability of student either a junior or a senior.

Solution:

From the above statement there are four classes, where freshmen is 35% and

sophomores is 30%,

So the probability of freshmen and sophomores as.

$P(freshmen) = 35\% = 0.35$

$P(sophomores) = 30\% = 0.3$

The probability of junior or senior student is one minus the probability that event does not occur.

$P(Junior\ or\ Senior)=1-P(freshman)-P(sophomore)$

$P(Junior\ or\ Senior)=1-0.35-0.30$

$P(Junior\ or\ Senior)=1-0.65$

$P(Junior\ or\ Senior)=0.35=35\%$

Therefore, the probability of student either a junior or a senior is 0.35 or percentage of probability is 35%.