Data exploration

This data comes from a study in which cows were given different diets and the amount of protein in their milk was measured each week.

There are 3 diets, 79 cows, and 19 weeks represented in this data set. The following tables show the number of observations available for each diet and the average amount of protein in the cows’ milk by diet and week. I think the second table would be better represented with a plot; I’ll send that to you by our next meeting.

Number of observations by diet
Diet n
Barley 425
Lupins 453
Mixed 459
Average protein level by diet and by week
Week Barley Lupins Mixed
1 3.89 3.76 3.86
2 3.64 3.43 3.54
3 3.50 3.37 3.35
4 3.38 3.29 3.28
5 3.48 3.24 3.34
6 3.39 3.28 3.39
7 3.47 3.19 3.33
8 3.50 3.31 3.40
9 3.51 3.35 3.44
10 3.52 3.27 3.44
11 3.46 3.23 3.35
12 3.43 3.21 3.37
13 3.51 3.33 3.41
14 3.51 3.25 3.37
15 3.54 3.26 3.45
16 3.60 3.27 3.57
17 3.68 3.25 3.51
18 3.64 3.30 3.45
19 3.64 3.21 3.40

At Week 1, cows on the barley diet had an average protein level of 3.89, compared to 3.76 and 3.86 for cows on the lupins and mixed diets, respectively.