the 154 tenth - graders at wilson high school were polled on whether they enjoyed their algebra or geometry…

the 154 tenth - graders at wilson high school were polled on whether they enjoyed their algebra or geometry course more. the results are shown below. algebra: 34 female, 33 male geometry: 40 female, 47 male use the drop - down menus to answer the questions. what is the probability that a randomly chosen tenth - grader is male? what is the probability that a randomly chosen tenth - grader is male given that the tenth - grader prefers geometry? are the events \male\ and \geometry\ independent?
Answer
Explanation:
Step1: Calculate total number of males
Total males = 33 + 47 = 80 Total students = 154
Step2: Calculate probability that a randomly - chosen tenth - grader is male
$P(\text{male})=\frac{80}{154}=\frac{40}{77}$
Step3: Calculate number of students who prefer geometry
Total students who prefer geometry = 40 + 47 = 87 Number of males who prefer geometry = 47
Step4: Calculate probability that a tenth - grader is male given that they prefer geometry
$P(\text{male}|\text{geometry})=\frac{47}{87}$
Step5: Check for independence
Two events $A$ (being male) and $B$ (preferring geometry) are independent if $P(A)\times P(B)=P(A\cap B)$. $P(\text{male})\times P(\text{geometry})=\frac{80}{154}\times\frac{87}{154}=\frac{80\times87}{154\times154}=\frac{6960}{23716}$ $P(\text{male}\cap\text{geometry})=\frac{47}{154}$ Since $\frac{80}{154}\times\frac{87}{154}\neq\frac{47}{154}$, the events are not independent.
Answer:
What is the probability that a randomly chosen tenth - grader is male? $\frac{40}{77}$ What is the probability that a randomly chosen tenth - grader is male given that the tenth - grader prefers geometry? $\frac{47}{87}$ Are the events "male" and "geometry" independent? No