Question

Scores on Professor Combs' Statistics Final Exams have a long
term history of being normally distributed, with a mean of μμ = 72
and a standard deviation of σσ = 9

**a.)** Find the probability that a single student
will score above a 77 on the Final exam.

**b.)** Find the probability that a single student
will score between a 67 and 77 on the Final exam.

**c.)** Find the probability that an entire class of
20 students will have a class average above a 77 on the exam.

**d)** Find the probability that an entire class of 20
students will have a class average between 67 and 77 on the Final
exam.

Answer #1

Student scores on Professors' Stats final exam are normally
distributed with a mean of 72 and a standard deviation of 6.9
Find the probability of the following:
**(use 4 decimal places)**
a.) The probability that one student chosen at random scores above
an 77.
b.) The probability that 20 students chosen at random have a mean
score above an 77.
c.) The probability that one student chosen at random scores
between a 67 and an 77.
d.) The probability that...

A professor knows that her statistics students' final exam
scores have a mean of 78 and a standard deviation of 9.3. In his
class, an "A" is any exam score of 90 or higher. This quarter she
has 25 students in her class. What is the probability that 4
students or more will score an "A" on the final exam?

A large statistics class consists of 250 students. On the final
exam, the professor worries that question 13 might be unfair. He
resolves to drop question 13 if less than 40% of the class
correctly answers the question. After grading 125 randomly selected
final exams (out of 250 taken), a student calls the professor and
asks if question 13 will be dropped. The professor looks at the
graded exams and notes that 46 of the 125 graded exams got question...

Student scores on the Stats final exam are normally distributed
with a mean of 75 and a standard deviation of 6.5
Find the probability of the following:
(use 4 decimal places)
a.) The probability that one student chosen at random scores above
an 80.
b.) The probability that 10 students chosen at random have a mean
score above an 80.
c.) The probability that one student chosen at random scores
between a 70 and an 80.
d.) The probability that...

a set of final examination grades in an introductory
statistics course is normally distributed with a mean of 77 and a
standard deviation of 7 complete parts a through d.
a. what is the probability that a student scored below 89 on this
exam
b. what is the probability that a student scored between 70 and
93
c. the probability is 15% that a student taking the test scores
higher than what grade
d. if the professor grades on a...

The scores for the final exam in a particular class are
approximately normally distributed with a meann of 78.4 points and
standard deviation of 5.7.
A. What score would a student nneed to score inn the top 20% of
sudent scores? Round two decimal places.
B. What is the probablity that a randomly selected group of 36
students will have a eman score of more than 80 points? Innclude a
probability statement. Round four decimal places.

Scores of students in a large Statistics class are normally
distributed with a mean of 75 points and a standard deviation of 5
points.
Find the probability that a student scores more than 80
points
If 100 students are picked at random, how many do you expect to
score below 70 points?
If top 10% of students obtain an A grade, how much should a
student obtain to get an A grade.
Suppose four students are picked at random, find...

Assume that statistics scores that are normally distributed with
a mean 75 and a standard deviation of 4.8 (a) Find the probability
that a randomly selected student has a score greater than 72. (b)
Find the probability that a randomly selected student has a score
between 70 and 80. (c) Find the statistics score separating the
bottom 99.5% from the top 0.5%. (d) Find the statistics score
separating the top 64.8% from the others.

Administrators are interested in knowing whether they have
significantly higher scores on final exams than the general
population of univerities (mu=76.5). After choosing a random sample
of 27 students, the administrators found that the average final
exam score for that sample was 82.6, with a standard error of
3.4.
Set up the criteria for making a decision. That is, find the
critical value. Let alpha = .05.

Scores on a recent national statistics exam were normally
distributed with a mean of 82 and a standard deviation of 4.
What is the probability that a randomly selected exam will have
a score of at least 87?
What percentage of exams will have scores between 80 and
85?
If the top 3% of test scores receive merit awards, what is the
lowest score eligible for an award?

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