Question

# A student takes a multiple-choice test that has 40 questions. Each question has 5 choices. The...

A student takes a multiple-choice test that has 40 questions. Each question has 5 choices. The
student did not study for the test and decides to randomly guess at each question. (Hint: The
probability of guessing correctly is 0.2.) Round the probability to four decimal places.
a) Find the probability the student gets exactly 10 problems correct._______________
(Show work.)
b) Calculate the mean.____________
c) Calculate the standard deviation._____________

Your flight has been delayed. At Philadelphia International Airport, 90% of recent flights have
arrived on time. A sample of 14 flights is studied. (Hint: Use Table A)
a) State why the scenario is binomial. Also, state n and p.
b) Find the probability exactly 14 of the flights were on time.______________
c) Find the probability at least 12 of the flights were on time._______________
d) Find the probability at most 10 of the flights were on time._______________
e) Find the probability less than 9 of the flights to be on time._____________ Is this unusual?______
f) Find the mean.__________________
g) Find the standard deviation.___________________

I will appreciate if someone helps me solve these two exercises but I also need to show me the work, explaining each step

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