Question

Each person in a group of college students was identified by graduating year and asked when he or she preferred taking classes: morning, afternoon, or evening. The results are shown in the table. Find the probability that the student preferred morning classes given he or she is a junior. Round to the nearest thousandth. Survey of Class Times Freshman Sophomore Junior Senior Morning 20 14 16 17 Afternoon 5 10 2 7 Evening 15 15 8 14

Answer 1

Answer:

0.615

Step-by-step explanation:

The frequency table is attached below.

We have to calculate, the probability that the student preferred morning classes given he or she is a junior.

i.e $P(\text{Morning }|\text{ Junior})$

We know that,

$P(A\ |\ B)=\dfrac{P(A\ \cap\ B)}{P(B)}$

So,

$P(\text{Morning }|\text{ Junior})=\dfrac{P(\text{Morning }\cap \text{ Junior})}{P(\text{Junior})}$

Putting the values from the table,

$\dfrac{P(\text{Morning }\cap \text{ Junior})}{P(\text{Junior})}=\dfrac{\frac{16}{143}}{\frac{26}{143}}=\dfrac{16}{26}=0.615$