This lesson investigates the growth of a shell fish in relation to the location or distance from sea water using data collected in a sandy, tidal inlet.

### Video

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### Tasks

There are two data files associated with this presentation: These two Excel files have the data for the 63 quadrats measured in this experimental study. The six variables are defined in the second file.**Task 1:**Draw the box-whisker plots for biomass by area for the three locations F (Furthest), M (Middle) and N (Near). Also draw the histograms for the three areas. Set up confidence intervals for the three mean biomass levels.**Task 2:**Draw box-whisker plots for the cockle densities per quadrat for the thrww areas and construct the confidence intervals for these mean densities at F, M and N. Report conclusions.**Task 3:**Carry out a one factor analysis of variance with biomass as response and area as the factor. Carry out one independent samples test for one pair of the means.**Task 4:**Carry out a two factor analysis of variance with the two factors group and area. Include the interaction between these two factors. Obtain the plot of means and the residual plot.**Task 5:**Draw the scatterplot between biomass and density. Interpret the plot and then fit a linear regression with biomass as response.**Task 6:**Add water level as a predictor and also the interaction between density and water level to the model, using the Undergraduate version to carry out this multiple regression.