19. Astudy has been made on pyrethrum flowers to determine the content of pyrethrin, a chemical used in insecticides. Four methods of extracting the chemical are used and samples are obtained from flowers stored under three conditions: fresh flowers, flowers stored for 1 year, and flowers stored for 1 year but treated. It is assumed that there is no interaction present. The data are as follows:

Suggest a model for the preceding information, and use the data to estimate its parameters.

Transcribed Image Text:

Pyrethrin Content, Percent Method Storage Condition A B C D 1 1.35 1.13 1.06 .98 23 2 1.40 1.23 1.26 1.22 1.49 1.46 1.40 1.35