# math

posted by ro

Statistics: Analyze student exam scores

Students were given an exam with 300 multiple choice questions. The distribution of the scores were normal and the mean was 195 with a standard deviation of 30. you may find it helpful to draw out this distribution before answering the questions below

16. What were the scores of the students who were within one standard deviation of the mean?

17. What percentf the students did that include?

18. What were the scores of students who scored in the middle of the class?

19. If a's are given to students who score 90% or above, what is the minimum z-score of someone getting an a?

20. Let's say you got 235 on this test. Your colleague is in a different section of this course. Her score was 82 out of 100 on her test. in her section the mean was 72 and the standard deviation was 7. Which one of you did better? (hint: compare z-scores)

1. PsyDAG

16. Z = (score-mean)/SD

Use Z = +1 and -1.

17. Mean ± 1 SD = 68.26% (Z Score is your score in terms of SD away from the mean.)

19. Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion (.9000) and its Z score.

20. Take the hint given.

## Similar Questions

1. ### Statistics

Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30. What were the scores of the students who were within one standard deviation …
2. ### math

Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30. You may find it helpful to draw out this distribution before answering the …
3. ### math

Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30. What was the score of students who scored in the middle of the class?
4. ### math

Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30. What was the score of students who scored in the middle of the class?
5. ### statistics

Answer the question(s) based on the following situation: 150 students in a math class take the final exam. The scores on the exam have an approximately normal distribution with center ì = 65 and standard deviation ó = 10.The third …
6. ### statistics and probability

It is known that an exam scores of students in STAT 2507 follow a normal distribution with a mean of 70% and a standard deviation of 9%. (A) If a student must obtain a mark of 50% to pass the exam, what proportion of students fail …
7. ### Statistics

The next three questions refer to the following situation. Data from previous years reveal that the distribution if first exam scores in an introductory statistics class is approximately normal with a mean of 72 and a standard deviation …
8. ### statistics

Scores on a national exam assume a normal distribution with a population mean of 50 and population standard deviation of 10 points. A sample of 36 exam scores was selected from UCA with a mean score of 58 points. Using a significance …
9. ### statistics

A state administered standardized reading exam is given to eighth grade students. The scores on this exam for all students statewide have a normal distribution with a mean of 506 and a standard deviation of 69. A local Junior High …
10. ### statistics

A state administered standardized reading exam is given to eighth grade students. The scores on this exam for all students statewide have a normal distribution with a mean of 507 and a standard deviation of 60. A local Junior High …

More Similar Questions