To ascertain the stability of vitamin C in reconstituted frozen orange juice concentrate stored in a refrigerator for a period of up to one week, the study Vitamin C Retention in Reconstituted Frozen Orange Juice was conducted by the Department of Human Nutrition and Foods at Virginia Tech. Three types of frozen orange juice concentrate were tested using 3 different time periods. The time periods refer to the number of days from when the orange juice was blended until it was tested. The results, in milligrams of ascorbic acid per liter, were recorded. Use a 0.05 level of significance to test the hypothesis that: a. there is no difference in ascorbic acid contents among the different brands of orange juice concentrate.
b. there is no difference in ascorbic acid contents for the different time periods.
c. the brands of orange juice concentrate and the number of days from the time the juice was blended until it was tested do not interact.

Brand 0 3 7
Richfood 52.6 54.2 49.4 49.2 42.7 48.8
49.8 46.5 42.8 53.2 40.4 47.6
Sealed-Sweet 56.0 48.0 48.8 44.0 49.2 44.0
49.6 48.4 44.0 42.4 42.0 43.2
Minute Maid 52.5 52.0 48.0 47.0 48.5 43.3
51.8 53.6 48.2 49.6 45.2 47.6