In: Statistics and Probability
Is there a difference between the means of the total of rooms per hotel in Crete and Southern Aegean Islands? Answer your question by calculating an appropriate, symmetric, 95% confidence interval using a Z statistic and equal standard deviations in the two populations. Explain your findings.
REGION ID
1= Crete
2=Southern Aegean Islands
3=Ionian Islands
Total_Rooms | Region_ID |
412 | 1 |
313 | 1 |
265 | 1 |
204 | 1 |
172 | 1 |
133 | 1 |
127 | 1 |
322 | 1 |
241 | 1 |
172 | 1 |
121 | 1 |
70 | 1 |
65 | 1 |
93 | 1 |
75 | 1 |
69 | 1 |
66 | 1 |
54 | 1 |
68 | 1 |
57 | 1 |
38 | 1 |
27 | 1 |
47 | 1 |
32 | 1 |
27 | 1 |
48 | 1 |
39 | 1 |
35 | 1 |
23 | 1 |
25 | 1 |
10 | 1 |
18 | 1 |
17 | 1 |
29 | 1 |
21 | 1 |
23 | 1 |
15 | 1 |
8 | 1 |
20 | 1 |
11 | 1 |
15 | 1 |
18 | 1 |
23 | 1 |
10 | 1 |
26 | 1 |
306 | 2 |
240 | 2 |
330 | 2 |
139 | 2 |
353 | 2 |
324 | 2 |
276 | 2 |
221 | 2 |
200 | 2 |
117 | 2 |
170 | 2 |
122 | 2 |
57 | 2 |
62 | 2 |
98 | 2 |
75 | 2 |
62 | 2 |
50 | 2 |
27 | 2 |
44 | 2 |
33 | 2 |
25 | 2 |
42 | 2 |
30 | 2 |
44 | 2 |
10 | 2 |
18 | 2 |
18 | 2 |
73 | 2 |
21 | 2 |
22 | 2 |
25 | 2 |
25 | 2 |
31 | 2 |
16 | 2 |
15 | 2 |
12 | 2 |
11 | 2 |
16 | 2 |
22 | 2 |
12 | 2 |
34 | 2 |
37 | 2 |
25 | 2 |
10 | 2 |
270 | 3 |
261 | 3 |
219 | 3 |
280 | 3 |
378 | 3 |
181 | 3 |
166 | 3 |
119 | 3 |
174 | 3 |
124 | 3 |
112 | 3 |
227 | 3 |
161 | 3 |
216 | 3 |
102 | 3 |
96 | 3 |
97 | 3 |
56 | 3 |
72 | 3 |
62 | 3 |
78 | 3 |
74 | 3 |
33 | 3 |
30 | 3 |
39 | 3 |
32 | 3 |
25 | 3 |
41 | 3 |
24 | 3 |
49 | 3 |
43 | 3 |
9 | 3 |
20 | 3 |
32 | 3 |
14 | 3 |
14 | 3 |
13 | 3 |
13 | 3 |
53 | 3 |
11 | 3 |
16 | 3 |
21 | 3 |
21 | 3 |
46 | 3 |
21 | 3 |
Sol:
Descriptive statistics | ||
Region1_Total_Rooms | Region2_Total_Rooms | |
Mean | 82.31111111 | 86.66666667 |
Variance | 9202.219192 | 10119.77273 |
Observations | 45 | 45 |
Pooled Variance | 9660.99596 |
Null hypothesis
Ho:
Ha:
alpha=0.05
Sp=pooled standard deviation
=sqrt((n1-1)*s1^2+(n2-1)*s2^2/(n1+n2-2)
=sqrt(45-1)*9202.219192+(45-1)*10119.77273/(45+45-2))
=98.29037
95% confidence interval for difference in means assuming equal variances is
(x1bar-x2bar)+-Z*Sp*sqrt(1/n1+1/n2)
=(82.3111-86.6667)+-1.96*98.29037*sqrt(1/45+1/45)
=-4.356+-1.96*98.29037*sqrt((1/45+1/45))
=-4.356+-40.614
=-4.356-40.614,-4.356+40.614
=-44.97,36.26
This confidence interval contains 0
Fail to reject Ho
Accept Ho
Conlclusion:
There is no sufficient statistical evidence by 95% confidence interval that
there is a difference between the means of the total of rooms per hotel in Crete and Southern Aegean Islands.