Exam 2 (Quarter 3) Review Sheet:
1) μ = 212 and σ = 12.
Answer and sketch each of the following:
a) What is the percentage of area over the interval between 212 & 224?
b) What is the percentage of area over the interval between 212 & 236?
c) What is the percentage of area over the interval between 200 & 224?
d) What is the probability that the data will fall between 200 and 236?
e) What is the probability that the data will fall between 200 and 212?
2) George is a senior citizen who takes medication to stabilize his (systolic) blood
pressure. He takes his blood pressure every day and from long experience, he knows the
average pressure is 137 with standard deviation of 6. Assume the blood pressure follows
a normal distribution. For the past ten days his blood pressure has been recorded in the
accompanying table, with x representing the systolic blood pressure:
Day
x
1
128
2
133
3
130
4
134
5
139
6
140
7
139
8
142
9
158
10
161
a) Create a control chart for the systolic blood pressure readings and plot the
data.
b) Do the data indicate the blood pressure distribution is “in control”? Explain
you answer!
3) The college health center did a campus-wide survey of students and found that 15%
smoke. A group of nine students randomly come together in the student cafeteria and sit
at the same table. Assume the cafeteria does not have a nonsmoking section and that a
student who ordinarily smokes will smoke at this time. Find the probability that:
a) no student at this table smokes.
b) at least one student smokes.
c) more than two students smoke.
d) from one to five smoke (including one and five).
4) On average only 4% of people have type AB blood.
a) What is the probability that there is a type AB blood donor among the first 5
people checked?
b) What is the probability that the first type AB blood donor will be found among
the first 6 people?
c) What’s the probability that we won’t find a Type AB blood donor before the
th
10 person?
5) Sarah is a court reporter. She makes an average of 0.2 errors per page.
a) What is the probability that she will make one or fewer errors on a single page?
b) What is the probability that she will type three successive pages with no errors?
c) What is the probability that she will type 5 successive pages with no errors?
d) What is the probability that she will type 4 pages with just 1 error?
6) Use the following values to answer the questions that follow:
73
82
77
68
73
64
68
77
78
76
68
77
66
68
67
78
87
79
70
73
80
78
77
76
79
77
74
76
79
77
73
74
78
a) Calculate μ
b) Calculate σ
c) Calculate a range of values centered about the mean in which about 68% of the
data will fall.
d) Calculate a range of values centered about the mean in which about 95% of the
data will fall.