In: Statistics and Probability
(1 point) The professor of a introductory calculus class has
stated that, historically, the distribution of test grades in the
course resemble a Normal distribution with a mean test mark of
?=63μ=63% and a standard deviation of ?=9σ=9%.
If using/finding ?z-values, use three decimals.
(a) What is the probability that a random chosen
test mark in this course will be at least 73%? Answer to four
decimals.
(b) In order to pass this course, a student must
have a test mark of at least 50%. What proportion of students will
not pass the calculus test? Use four decimals in your
answer.
(c) The top 6% of students writing the test will
receive a letter grade of at least an A in the course. To two
decimal places, find the minimum test mark needed on the calculus
final to earn a letter grade of at least an A in the
course.
%
(d) Suppose this professor randomly picked 27
tests, observing the earned mark on each. What is the probability
that 5 of these have a test grade of less than 50%? Use four
decimals in your answer.
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