Question

Cigarets randomlyselected from 2 popular brands are analyzed to determine their nicotine content (in mg). The results are as follows.

Brand A: n1=10 x₁=32.1 S₁=4.1

Brand B: n₂=15 x₂=34.9 S₂=3.3

Tets the a=0.05 , whether the average nicotine of brand A is less than standard B

Answer 1

So:

its t test for difference in means assuming unequal variances,

H0:

H1:

alpha=0.05

test statitsic:

t=x1-x2/sqrt(n1-1)s1^2+(n2-1)s2^2/n1+n2-2(1/n1+1/n2)

t=(32.1-34.9)/sqrt((10-1)4.1^2+(15-1)3.3^2/10+15-2(1/10)+(1/15))

t=-1.805

using the p value approach,the p vaue is p=0.0447, and since

p<0.05

Reject Null hypothesis

Accept alternatiev Hypothesis.

Conclusion:
There is suffcicient evidence at 5% level of significance to conclude that he average nicotine of brand A is less than standard B