# probabilityv

posted by lisa

and the e ect it has on students' grades. The following data were compiled, based on a sample of students.
Student's Absent Medium Absent
Low 1 9 8
Medium 6 35 7
High 8 9 2
a. What is the probability that a randomly selected student will have a low grade?

This would be 1/15 + 9/53 + 8/17 right?

b. What is the probability that a randomly selected student absent frequently?

8/18 + 7/48 + 2/19

c. Are grades and frequency in absent independent events? Why?

Not sure but i think they are dependent

d. Knowing that a randomly selected student has high grade, what is the probability that student is absent frequently?
2/19
e. What is the probability that a randomly selected student has either high grade or absent frequently?
I don't know how to calculate this

1. PsyDAG

a. total of low grade students/grand total of students = 18/85

b. total of frequently absent students/grand total of students

c. Yes,try a Chi-squared (X^2) test to show why

d. Yes!

e. Either-or probabilities are found by adding the probabilities of the individual events. Total number of high grade/grand total + total number of absent frequently/grand total

## Similar Questions

1. ### math

Attendance records at a school show the number of days each student was absent during the year. The days absent for each student were as follows: 8 2 4 3 2 7 6 0 9 3 3 4 2 4 6 Create a dot plot for this data
2. ### Math

Suppose 8 out of every 20 students are absent from school less than five days a year. Predict how many students would be absent from school less than five days a year out of 40,000 students.
3. ### Math

Suppose 8 out of every 20 students are absent from school less than 5 days a year. Predict how many students would be absent from school less than 5 days a year out of 40,000 students
4. ### math

Suppose 8 out of every 20 students are absent from school less than five days a year. Predict how many students would be absent from school less than five days a year out of 40,000 students.
5. ### Math Help

Suppose that each student in stat. has a 9% chance of missing class on any given day and that student attendance is independent. In a stat. class of 20 students, find the probability that: 1) no student is absent 2) one student is …

Suppose that each student in stat. has a 9% chance of missing class on any given day and that student attendance is independent. In a stat. class of 20 students, find the probability that: 1) no student is absent =15.16 2) one student …
7. ### math

there are 13 boys and 14 girls in mrs greens class if 3 of the students are absent today what is the ratio of students absent to students present?
8. ### math

suppose 8 out of every 20 students are absent from school less than 5 days a year. Predict how many students would be absent from school less than 5 days a year out of 40,000 students.
9. ### Math

On Thursday,1/6 of students in class were absent.If there are 36 students in total,how many students were absent?
10. ### Percentage

On a rainy day,out of 150 students in a school 25 were absent.find the percentage of students absent from the school?

More Similar Questions