Question

3. A Sci-fi aficionado claims space creatures from another Galaxy have an average mass of 25kg (~55pounds). A random sample of 40 of these creatures has a mean mass of 23.2kg and a (sample) standard deviation of 6 kg.

a) State the null and alternative hypotheses. b) Determine the P-Value

c) State the outcome of the test at ?=0.01

Answer 1

given data are:-

sample size(n) = 40

sample mean () = 23.2

sample sd(s) = 6

here, as the sample sd is known we will do 1 sample t test for mean.

a).hypothesis:-

test statistic be:-

degrees of freedom = (n-1) = (40-1) = 39

b).p value :-

[ in any blank cell of excel type =T.DIST(-1.897,39,TRUE) press enter]

c).decision:-

p value = 0.0653 >0.01 (alpha)

so, we fail to reject the null hypothesis.

conclusion:-

there is sufficient evidence to support the claim that space creatures from another Galaxy have an average mass of 25kg at 0.01 level of significance.

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