Question

A comparison was made between number of cigarettes smoked in a day by a sample of females and a sample of males.

Sex female male

N 32 18

Mean 6.74 4.32

StDev 7.36 5.52

SE Mean 1.3 1.3

(a) To start, we can write n₁ = 32. Identify each of the following, choosing from the numbers 18, 6.74, 4.32, 7.36, or 5.52 to fill in each of the blanks.

n2	=
s1	=
s2	=
x1	=
x2	=

(b) How is it possible that the standard errors are equal, even though the standard deviation was higher for the females?

because the females have a larger mean

because the females have a larger sample size     

(c) Side-by-side boxplots are constructed to compare data for males and females. This is focusing on which process?

probability

statistical inference     

displaying and summarizing

data production

(d) Average number of cigarettes smoked per day may be the same for all male and female students. This is focusing on which process?

probability

statistical inference     

data production

displaying and summarizing

(e) Instead of asking, "On average, how many cigarettes do you smoke each day?" students were asked, "How many cigarettes did you smoke yesterday?" This is focusing on which process?

probability

statistical inference     

data production

displaying and summarizing

(f) If mean number of cigarettes smoked per day were identical for all males and females, it wouldn't be too unlikely to see sample means as different as 6.74 and 4.32. This is focusing on which process?

probability

data production     

displaying and summarizing

statistical inference

Answer 1

a)

n₂=18

s₁=7.36

s₂=5.52

x₁=6.74

x₂=4.32

(b) How is it possible that the standard errors are equal, even though the standard deviation was higher for the females?

because the females have a larger sample size   

(c) Side-by-side boxplots are constructed to compare data for males and females. This is focusing on which process?

displaying and summarizing

(d) Average number of cigarettes smoked per day may be the same for all male and female students. This is focusing on which process?

probability

(e) Instead of asking, "On average, how many cigarettes do you smoke each day?" students were asked, "How many cigarettes did you smoke yesterday?" This is focusing on which process?

statistical inference     

(f) If mean number of cigarettes smoked per day were identical for all males and females, it wouldn't be too unlikely to see sample means as different as 6.74 and 4.32. This is focusing on which process?

data production