A professor has noticed that, even though attendance is not a component of the f

Question

A professor has noticed that, even though attendance is not a component of the final grade for the class, students that attend regularly generally get better grades. In fact, 42% of those who come to class on a regular basis receive A's. Only 4% who do not attend regularly get As. Overall, 60% o students attend regularly. Based on this class profile suppose we are rando y selecting a single student on this class, and answer he guestions eo Hint # 1 : pretend that there are 100 students in he class and use the values given in he problem to construct the appropriate contingency tabie Round ell frequenc es to the nearest integer Hint #2: No joke, you really need to use hint #1. Hint # 3: The first step to using hint #1 is to calculate the totals for those who attend regularly and do not attend regularly. A) P(receives A's | attends regularly)0.70X Use 2-decimal precision in your answer B) PCreceives A's I does not attend regulany)-0.10x Use 2-decimal precision in your answer C) P(receives A's) = 0.46 Use 3-decimal precision in your answer D) P(attends regularly | receives A's) 091 Use 3-decimal precision in your answer E) P(does not attend regularly I does not receive A's) = 0.67 Use 3-decimal precision in your answer

Explanation / Answer

Using Hint # 1 as there are 1000 students in the class.

So, number of students who attend the class regularly = 1000 * 0.60 = 600

That means number of students who don't attend class regularly = 1000 * ( 1- 0.60) = 400

Here number of students who comes to classes got A = 600 * 0.42 = 252

Number of students who come to classes doesn't get A = 600 * 0.58 = 348

Number of students who don't come to classes get A = 400 * 0.04 = 16

Number of students who don't come to classes doesn't get A = 400 * 0.96 = 384

(a) P(Receive A's l Attend regularly) = 0.42

(b) P(Receive A's l doesn't attend regularly) = 0.04

(c) Pr( Receive A's ) = P(Receive A's l Attend regularly) * P(attends regularly) + P(Receive A's l doesn't attend regularly) * Pr(doesn't attend regulary)

= 0.60 * 0.42 + 0.40 * 0.04 = 0.268

or can be solved as

Pr( Receive A's ) = (252 + 16)/1000 = 0.268

(d) P(Attendes regularll Get A's) = 252/ 268 = 0.940

(e) P(does not attends regularly l does not receivesA's) = Students doesn't attend regularly/ students doesn't receives A's

=P(does not attends regularly and does not receives A's)/ P(does not receivesA's)

= 384/(1000 - 268) = 0.525

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.