3. (10 pts) Monoamine oxidase (MAO) is an enzyme that is thought to play arole i

ID: 3170788 • Letter: 3

Question

3. (10 pts) Monoamine oxidase (MAO) is an enzyme that is thought to play arole in the regulation of behavior. To see whether different categories of schizophrenic patients have different levels of MAO activity, researchers collected blood specimens from 42 patients and measured the MAO activity in the platelets. The results are summarized in the accompanying table. (values are expressed as nmol benzyladehyde produce/10S platletshour) Calculations based on the raw data yielded SS(between 3136.12 and SS(within) J418.25. MAO Activity DIAGNOSIS Mean SD No. of Patients Chronic undifferentiated schizophrenic 9.81 3.62 18 Undifferentiated with paranoid features 6.28 2.88 16 Paranoid schizophrenic 5.97 3.19 (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) Construct the ANOVA table and test the global null hypothesis at 30.05. (c) Calculate the pooled standard deviation, spooled.

Explanation / Answer

Result:

a).

Based on graph, null hypothesis is not true because first group mean is larger than other two.

b).

Source

Treatment

136.12

68.06

6.3463

Error

418.25

10.7244

Total

554.37

Table value of F with (DF1=2, DF2=39 ) =3.24

Calculated F=6.3463 > 3.24 the table value

The null hypothesis is rejected.

The data indicate there is a significant difference among the three groups

Pooled standard deviation =sqrt(MSS) = sqrt(10.7244)

=3.274813