Question

In a laboratory experiment to investigate the effect of sewage effluent on the fecundity of freshwater shrimps (Gammarus pulex) a number of populations of shrimps were placed into large vessels with different concentrations of organic matter. Females from each vessel were then dissected to see how many eggs they were carrying.

Organic matter (g /l)	0.5	1.0	1.5	2.0	2.5	3.0	3.5	4.0	4.5	5.0
Mean fecundity	45	40	36	29	27	20	15	10	10	8

(i) Plot a graph of the relationship using R/SPSS. Obtain estimates of the slope and intercept of the line of best fit through the data and predict the mean fecundity of Gammarus when reared with 3.2 g/l organic matter.

(ii) Test the NH that there is no underlying linear relationship (i.e. zero slope at population level) between fecundity and organic matter. Visually examine the distribution of residuals and comment on whether the assumptions of the test appear valid. What is the estimated variance (i.e. the estimated “error”) of residuals around the fitted line?

Answer 1

Dear, inorder to understand the concept instead of providing software results I provided a well explained solution. Also the plot is provided with prescribed software in the question. Hope it will satisfies you.. If you have any doubt please comment it ... I will help you... If you are satisfied please Thumbs Up dear... Thanks in advance for your support and love..