probability and statistics
Suppose every student in your class got a score of 85% on an exam. What are the mean and standard deviation of those exam scores without doing any calculations?
I want to say the mean is 100 and the standard deviation is 1 but I don't know why. If all students scored 85% that would be 100% of them so that's how I got 100 but I don't understand how to reach the standard deviation.

Ummmh, if everybody got an 85, wouldn't the average be 85 ??? , so mean = 85
and since nobody "deviated" from that score, wouldn't the standard deviation be zero ????posted by Reiny

Suppose the scores of students on an exam are normally distributed with a mean of 507 and a standard deviation of 97. According to the empirical rule, what percentage of students scored between 410 and 604 on the exam?
posted by Anonymous
Respond to this Question
Similar Questions

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 
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 
statistics
Can you please tell me how to solve for the following? Pedro took an exam in a class in which the mean was 64 with a standard deviation of 6. If his z score was +3, what was his exam score? A students commute to school is normally 
math
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 
Statistics
In Professor Smith's statistics course, the correlation between students' total scores before the final exam and their final exam scores is r = 0.67. The preexam totals for all students in the course have a mean of 275 and a 
statistics
say that you have a distribution of exam scores with a mean of 57 and a standard deviation of 7. if a student in the class has a standard score equal to 2.429, what would their raw score on the exam be? 
Statistics
5. Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6. a. What is the probability that a randomly selected exam will have a score of at least 71? b. What 
statistics
Suppose that the test scores for a college entrance exam are normally distributed with a mean of 450 and a standard deviation of 100. If a student is selected at random what is the probability that the student will score above 
stats
Relatively speaking, which statistics exam did you do better on? On your first statistics exam you scored a 72 and on the second exam you scored an 89. Hey, youâ€™re improving! Or are you? On the first exam, the class mean was 71 
Math Statistics
Answer the following. Show your work to get credit. Exam scores are normally distributed with a mean of 81 and a standard deviation of 9. a) What is the minimum score one must have to be in the top 4% of the students taking the