Question

One-hundred students were allowed to re-take an exam for their math course. The probability distribution shows how studying for the latest exam affected their grade when compared with the first time they took the exam. What is the probability that a student who studied for the exam saw an increase in their exam grade? Round to the nearest thousandth. Exam Grades Studied Did Not Study Totals Raise in Grade 0.52 0.06 0.58 No Raise in Grade 0.05 0.37 0.42 Totals 0.57 0.43 1

A. 0.088

B. 0.897

C. 0.912

D. 0.570

Answer 1

Explanation:

0.912 (C) is the probability that a student who saw an increase in their grade had studied

Answer 2

Answer: C. 0.912

Explanation:

From the given table, The probability of students who studied = 0.57

The probability of student who studied for the exam and who saw a raise in their exam grade = 0.52

Now, the probability that a student who studied for the exam saw an increase in their exam grade is given by :

`\text{P(student studied for exam saw an increase in grade)}=\frac{\text{P(student  studied and saw raise in grade)}}{\text{P(student studied)}}\\\\\Rightarrow\text{P(student studied for exam saw an increase in grade)}=(0.52)/(0.57)\\=0.91228070175\approx0.912`