In: Statistics and Probability
Complete the following chi square test:Show all work.
Example Chi Sq.
40% of Americans say that their favorite pastime is sports, 40% say that it’s time with their family, and 20% name something else. A survey of your neighborhood finds that 10 people report a preference for sports, 15 for being with their families, and 5 something else. Do your neighbors differ from Americans overall?
Activity Observed Expected EF O-E (O-E)2 (O-E)2/E
Sport 10 .4 12 -2 4 .33
Fam 15 .4 12 3 9 .75
Other 5 .2 6 -1 1 .17
30 2 = ∑ (O-E)2/E = 1.25
Is Paris, Chicago, or NY the most romantic city?
City Observed Expected EF O-E (O-E)2 (O-E)2/E
Chicago 2 .33
NY 40 .33
Paris 58 .33
100 2 = ∑ (O-E)2/E =
Is there a significant correlation between these two sets of numbers?
Weight Time
46 44
55 27
61 24
75 24
64 36
75 36
71 44
59 44
64 120
67 29
| category | observed frequencey, O | expected proportion | expected frequency,E | (O-E)²/E | ||
| sports | 10 | 0.400 | 12.00 | 0.333 | ||
| family | 15 | 0.400 | 12.00 | 0.750 | ||
| something else | 5 | 0.200 | 6.00 | 0.167 |
chi square test statistic,X² = Σ(O-E)²/E =
1.250
level of significance, α= 0.05
Degree of freedom=k-1= 3 -
1 = 2
P value = 0.5353 [ excel function:
=chisq.dist.rt(test-stat,df) ]
Decision: P value >α , Do not reject Ho
so, neighbors do not differ from Americans overall
................
| category | observed frequencey, O | expected proportion | expected frequency,E | (O-E)²/E | ||
| chicago | 2 | 0.333 | 33.33 | 29.453 | ||
| NY | 40 | 0.333 | 33.33 | 1.333 | ||
| PARIS | 58 | 0.333 | 33.33 | 18.253 |
chi square test statistic,X² = Σ(O-E)²/E =
49.040
level of significance, α= 0.05
Degree of freedom=k-1= 3 -
1 = 2
P value = 0.0000 [ excel function:
=chisq.dist.rt(test-stat,df) ]
Decision: P value < α, Reject Ho
...................
| ΣX | ΣY | Σ(x-x̅)² | Σ(y-ȳ)² | Σ(x-x̅)(y-ȳ) | |
| total sum | 637 | 428 | 738.1 | 7203.6 | -143.60 |
| mean | 63.70 | 42.80 | SSxx | SSyy | SSxy |
correlation coefficient , r = Sxy/√(Sx.Sy)
= -0.0623
correlation hypothesis test
Ho: ρ = 0
Ha: ρ ╪ 0
n= 10
alpha,α = 0.05
correlation , r= -0.0623
t-test statistic = r*√(n-2)/√(1-r²) =
-0.176
DF=n-2 = 8
p-value = 0.8643
Decison: P value > α, So, Do not reject
Ho
SO, There is not any correlation
......................
THANKS
revert back for doubt
please upvote