MATH 110 Statistics Exam Opener Answers

MATH 110Statistics
Exam Opener
Exam Page 1
Look at the following data and see if you can identify any outliers:
89 9 94 55 63 77 4 70 83 61 345 65 69

94, 4, 70


-6.0 points


Instructor Comments

You can see the correct outliers in the answer key.

Answer Key

Look at the following data and see if you can identify any outliers:
89 9 94 55 63 77 4 70 83 61 345 65 69

The outliers are:
4 9 345


Exam Page 2
Consider the following set of data:
{25, 22, 14, 35, 44, 8, 18, 30, 44}
a) Find the median.

25

b) Find the mode of this set.

44



Instructor Comments

Very good.

Answer Key

, Consider the following set of data:
{25, 22, 14, 35, 44, 8, 18, 30, 44}
a) Find the median.

a) In order to find the median, we must first put the numbers in ascending order:

8, 14, 18, 22, 25, 30, 35, 44, 44.

Notice that the “middle” number is 25. So, Median = 25.

b) Find the mode of this set.

b) The number that occurs most is 44. So, the mode is 44.




Exam Page 3
Suppose A and B are two events with probabilities:

P(A)=.70,P(B^c )=.75,P(A∩B)=.20.


Find the following:
a) P(A∪B).

P(A∪B)=P(A)+P(B)-P(AnB)=.7+.75-(.7)(.75)=.20
P(A∪B)=P(A)+P(B)-P(AnB)=.7+.75-.525=.20
P(A∪B)=P(A)+P(B)-P(AnB)=.7+.75-.525=.20
P(A∪B)=P(A)+P(B)-P(AnB)=1.45-.525=.20
P(A∪B)=P(A)+P(B)-P(AnB)=.925=.20
P(A∪B)=P(A)+P(B)-P(AnB)=.20
.925
P(A∪B)=.216



b) P(Ac).

P(Ac)=1-P(A)+1-(.70)=0.3


c) P(B).