Question

The average weight of a turkey is 15 lbs. A researcher contracted by Superfoodmart takes a random survey of households in your village asking what size turkey they intend to buy. The values below represent the anticipated weight in lbs reported by each sampled household. {10, 9, 8, 6, 14, 15, 9, 8, 4}

a) Calculate t-observed for the comparison of your village and population mean.

b) Using alpha .05, two-tailed, what decision would you make regarding the comparison of your village to the national population mean?

c) Report Cohen's d for the comparison between your village and the general population. Report it in terms of absolute value.

Answer 1

Here, the hypothesis to be tested is

Now,

and

therefore,

s = 3.4986

a) Hence, observed t for the comparison of the village and population mean is

t = (9.22 -15)/(3.4986/3)

= -4.956

b) Using alpha = 0.5, two tailed,

Since t-observed = -4.956 < -0.706

Hence, we decide that the village mean is not equal to the hypothesized population mean.

c) The Cohen's d for the comparison between the village and the general population is

= |(9.22 - 15)/3.4986|

= 1.652