Question

given the table below, what is the probability that a randomly chosen student:
is in 12th grade?
rides the bus to school?
is a 10th grader who walks to school?
a senior who drives to school (or rides in a car)?
bikes to school given that they are in 11th grade?
is an upperclassman (junior or senior) given they walk to school?

Explanation:

Step1: Probability of 12th grade

Total students = 1388, 12th grade students = 441
$\text{Probability} = \frac{441}{1388}$

Step2: Probability of riding bus

Bus riders = 612
$\text{Probability} = \frac{612}{1388}$

Step3: Probability of 10th grader walking

10th graders walking = 103
$\text{Probability} = \frac{103}{1388}$

Step4: Probability of senior driving (car)

Seniors (12th grade) driving = 168
$\text{Probability} = \frac{168}{1388}$

Step5: Probability of biking given 11th grade

11th graders biking = 90, 11th grade total = 466
$\text{Probability} = \frac{90}{466}$

Step6: Probability of upperclassman given walking

Upperclassmen (11+12) walking = 72+84=156, total walking =259
$\text{Probability} = \frac{156}{259}$

Answer:

$\frac{441}{1388}$
$\frac{612}{1388}$
$\frac{103}{1388}$
$\frac{168}{1388}$
$\frac{90}{466}$
$\frac{156}{259}$