In: Statistics and Probability
Divide the data into three groups according to age: under 25, 26 to 49, and over 50.
Use ANOVA to test the claim that all three of these groups have the same mean balance on their Visa card.
Be sure to write down the mean and standard deviation for each group!
Age <25 26-49 over 50
n = n = n =
x = x = x =
s = s = s =
The data collected below comes from people that live in Salinas. Listed below are the genders, ages and current balance on one specific type of Visa card.
Gender |
Balance |
Age |
M |
235 |
19 |
M |
122 |
24 |
M |
1752 |
55 |
M |
1543 |
62 |
M |
1655 |
34 |
M |
0 |
19 |
M |
84 |
22 |
M |
355 |
26 |
M |
299 |
28 |
M |
2404 |
45 |
M |
848 |
54 |
M |
667 |
71 |
M |
1248 |
32 |
M |
7746 |
38 |
M |
0 |
41 |
M |
8329 |
51 |
M |
486 |
34 |
M |
554 |
38 |
M |
874 |
54 |
F |
601 |
62 |
F |
56 |
80 |
F |
472 |
27 |
F |
59 |
18 |
F |
4233 |
49 |
F |
2544 |
58 |
F |
109 |
22 |
F |
235 |
24 |
F |
644 |
36 |
F |
3484 |
57 |
F |
1509 |
27 |
F |
624 |
30 |
F |
3324 |
59 |
F |
2268 |
33 |
F |
495 |
19 |
F |
0 |
26 |
The hypothesis being tested is:
H0: µ1 = µ2 = µ3
Ha: Not all means are equal
Age < 25 | 26-49 | over 50 | |||
19 | 34 | 55 | |||
24 | 26 | 62 | |||
19 | 28 | 54 | |||
22 | 45 | 71 | |||
27 | 32 | 51 | |||
18 | 38 | 54 | |||
22 | 41 | 62 | |||
24 | 34 | 80 | |||
19 | 38 | 58 | |||
49 | 57 | ||||
36 | 59 | ||||
27 | |||||
30 | |||||
33 | |||||
26 | |||||
n = 9 | n = 15 | n = 11 | |||
x = 21.6 | x = 34.5 | x = 60.3 | |||
s = 3.05 | s = 6.88 | s = 8.49 | |||
21.6 | 9 | 3.05 | Age < 25 | ||
34.5 | 15 | 6.88 | 26-49 | ||
60.3 | 11 | 8.49 | over 50 | ||
39.3 | 35 | 16.70 | Total | ||
ANOVA table | |||||
Source | SS | df | MS | F | p-value |
Treatment | 8,022.55 | 2 | 4,011.274 | 88.15 | 9.62E-14 |
Error | 1,456.14 | 32 | 45.504 | ||
Total | 9,478.69 | 34 |
The p-value is 0.000.
Since the p-value (0.000) is less than the significance level (0.05), we can reject the null hypothesis.
Therefore, we cannot conclude that all three of these groups have the same mean balance on their Visa card.