Given n1 = 10, n2 = 12 (less than 30, use t test)
x̄1 = 71, x̄2 = 69
s12 = 3 s22 = 2
H0 :mean weight of boys and girls are same,
(i.e. H0: µ1= µ2)
H1 : mean weight of boys is more than girls
(i.e. H1: µ1 > µ2) …(upper tail test)
The test statistic is
For (n1 + n2 – 2) = (10 + 12 -2) = 20 degrees of freedom the upper tail critical value for 5% level of significance k2 = 1.73
Herz tcal > k2/tcal lies in (RR) rejection region.
∴ H0 is rejected and H1 is accepted.
Conclusion : Mean weight of boys is more than girls.