(Solved): 11.4.1 Monoamine oxidase (MAO) is an enzyme that is thought to play a role in the regulation of beh ...

11.4.1 Monoamine oxidase (MAO) is an enzyme that is thought to play a role in the regulation of behavior. To see whether different categories of patients with schizophrenia have different levels of MAO activity, researchers collected blood specimens from 42 patients and measured the MAO activity in the platelets. The results are partially summarized in the accompanying tables. (Values are expressed as nmol benzylaldehyde product $/10^8$ platelets/hour. ${)}^3$ (a) Dotplots of these data follow. Based on this graphical display, does it appear that the null hypothesis is true? Why or why not? (b) How many degrees of freedom are there for the ANOVA $F$ test? (c) Compute the value of $F_x$. (d) The $P$-value for the test is 0.004 . If $?=0.05$, what is your conclusion regarding the global null hypothesis? (c) Calculate the pooled standard deviation $s_{\text{pooled. }}$