Problems on statistics and probability are presented. The answers to these problems are at the bottom of the page.

Given the data set
4 , 10 , 7 , 7 , 6 , 9 , 3 , 8 , 9
Find
a) the mode,
b) the median,
c) the mean,
d) the sample standard deviation.
e) If we replace the data value 6 in the data set above by 24, will the standard deviation increase, decrease or stay the same?

Find x and y so that the ordered data set has a mean of 42 and a median of 35.
17 , 22 , 26 , 29 , 34 , x , 42 , 67 , 70 , y

Given the data set
62 , 65 , 68 , 70 , 72 , 74 , 76 , 78 , 80 , 82 , 96 , 101,
find
a) the median,
b) the first quartile,
c) the third quartile,
c) the interquartile range (IQR).

The exam grades of 7 students are given below.
70 , 66 , 72 , 96 , 46 , 90 , 50
Find
a) the mean
b) the sample standard deviation

Twenty four people had a blood test and the results are shown below.
A , B , B , AB , AB , B , O , O , AB , O , B , A
AB , A , O , O , AB , B , O , A , AB , O , B , A
a) Construct a frequency distribution for the data.
b) If a person is selected randomly from the group of twenty four people, what is the probability that his/her blood type is not O?
Answers to the Above Problems
More references on elementary statistics and probabilities.

