Average,Chebyshev’s theorem,skewness
please solve following quesitons
Q#1The average IQ of 10 students in a mathematics course is 114.If 9 of the students have IQ’s of 101, 125, 118, 128, 106, 115, 99,118 and 109. What must be the other IQ? Feeling
Q#2
The grade-point averages of 20 college seniors selected at random from the graduating class are as follows:
3.2,1.9,2.7,2.4,2.8,2.9,3.8,3.0,2.5,3.3,1.8,2.5,3. 7,2.8,2.0,3.2,2.3,2.1,2.5,1.9
Calculate the percentage of grade point averages falling in the intervals X_+2S and_+3S . Do these results agree with Chebyshev’s theorem?
Q3
Calculate skewness from the following distribution by
a.the Bowley’s formula
b.the Pearsonian method
data
Groups: 35-39,40-44,45-49,50-54,55-59,60-64,65-69.
Frequency: 13,15,17,28,12,10,5 respectively.
Groups
frequency
35-39
40-44
45-49
50-54
55-59
60-64
65-69
13
15
17
28
12
10
5
Thanks