The appropriate statistical test for our data is a two-proportion z-test because our question of interest compares proportions of two different populations.
1) p1-p2 = The difference between the true proportion of freshmen who attended at least one NOHS sporting event in the past school year and seniors who attended
at least one NOHS sporting event in the past school year.
2) Ho: p1-p2 = 0
3) Ha: p1-p2<0
4)
Alpha: 0.05
5)
6) i. Samples are independent
and random
ii. Sample sizes
are sufficiently large:
n1(p1)=51(.784)=40≥10
n1(1-P1)=51(.216)=11≥10
n2(P2)=27(.889)=24≥10
N2(1-P2)=27(.111)=3<10
(Though
one sample does not meet the size
requirement, we will proceed with caution.)
7) z
= -1.25
8) p-value = 0.105