Question

example 3
suppose a researcher collected student data on ccds campus and asked students what year they were and if they worked outside of school or not. the results are as follows:

c) find the probability that a student is a first year and has 1 job.
how do you find the answer for part (c)?
o a subtract the total number of 1st year students from the total number of students with 1 job.
o b find the cell that is intersected by the 1st year student row and 1 job column.
o c add the total of 1st year students with the total number of students with 1 job.

Explanation:

In probability for two - way tables, when finding the probability of an "AND" event (a student is a first - year and has 1 job), we look at the cell where the relevant row (1st year student) and column (1 job) intersect. This cell value represents the number of students who satisfy both conditions. Subtracting (option a) or adding (option c) values from different parts of the table does not give the count of students who are both first - year and have 1 job. Only looking at the intersection cell (option b) gives the correct count for calculating the probability \(P=\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}\).

Answer:

B. Find the cell that is intersected by the "1st year student" row and "1 job" column.