In: Statistics and Probability
Use a one-way ANOVA test to study the price difference between cruelty-free products and those tested on animals
Products | Cruelty free | Tested on animals |
Foundation | 39 | 43 |
Concealer | 29 | 28 |
Lipstick | 19 | 22 |
Serum | 54 | 41 |
Perfume mist | 12 | 13.07 |
Body oil | 26 | 32 |
Soap | 12 | 15 |
These are a few products from well known brands and can be found easily online.
Null hypo: There is no significance difference between animal tested and cruelty free products prices.
VS
Alternative hypo: There is significance difference between animal tested and cruelty free products prices.
We will conduct the test at 0.05 level of significance.
ANOVA | ||||||
Source of Variation | SS | df | MS (SS/df) | F (SSb/ SSr) | P-value (P > F) | F crit |
Between Groups | 0.673207 | 1 (k - 1) | 0.673207 | 0.003625 | 0.953 | 4.75 |
Within Groups | 2228.801 | 12 (n - k) | 185.7334 | |||
Total | 2229.475 | 13 |
As you can see that p-value > 0.05 and also Test stat (F) < critical (F crit )
WE don't reject the null hypothesis and conclude that there is no significant difference between cruelty free and animal tested product prices at 0.05 level of significance.
This is ANOVA - Single Factor. We first need to find the and . They are 'Total variance' and 'Variance in between the treatments' respectively.
We know
=
Grand total = 385.07 Sum of individual squares = 12820.82
= 2229.48
=
Note: We have to separately sum for all the treatment.
=
= 10592.7
=0.673
2228.80
We can also use excel data analysis function
Steps: