In many countries, grains and cereals are the primary food source. The authors of the ar...

In many countries, grains and cereals are the primary food source. The authors of the article “Mineral Contents of Cereal Grains as Affected by Storage and Insect Infestation” ( Journal of Stored Products Research [1992]: 147–151) investigated the effects of storage period on the mineral content of maize. Four storage periods were considered: 0 months (no storage), 1 month, 2 months, and 4 months. Twenty-four containers of maize were randomly divided into four groups of six each. The iron content (mg/100 g dry weight) of the first group of six was measured immediately (0 months of storage), the second six were measured after 1 month in storage, etc. The following summary quantities are consistent with information in the article:

a. Use a test with α = .05 to decide whether true average iron content is the same for all four storage periods.

b. If appropriate, carry out a multiple comparison analysis.