that the samples were drawn from the same district which has the s.d. of 11
kgs per acre?
Solution : Set ??????
0: ??????
1 = ??????
2
Given �
1= 100 , �̅
1 =210 , ??????= 150, �
2 = 150 , �̅
2 =220
At 5 % level of significance, |�
??????| =1.96
Z =
�̅
1 − �̅
2
??????√(
1
??????1
)+(
1
??????2
)
By computation, z = -7.04
Calculated value, |�| =7.04 >3
??????
0 is rejected.
The difference is highly significant.
UNIT-5
1. Weights in kilograms of 10 students are given below: 38,40,45,53,47,43,55,
48,52, 49. Can we say that the mean weight of the distribution of all students from
which the above sample was drawn is equal to 45.
Solution: Set ??????
0: ?????? = �̅
Calculating ,�̅ =47,n =10 , �
2
=28,s =5.292
Test statistic t =1.154
D.F=n-1=9
Table value =2.26
Calculated value =1.154
Calculated value < Table value.
??????
0 is accepted.
The difference is not significant.
________________________________________________________________
2. The A random sample of 10 boys has the following I.Q(Intelligent Quotients).
70,120,110,101,88,83,95,98,107,100.Do these supports the assumption of a
population mean I.Q. of 100? )26.2
05.0
( =t )26.2
05.0
( =t