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Biostatistics

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EXERCISES 369<br />

The SAS System<br />

Analysis of Variance Procedure<br />

Dependent Variable: TIME<br />

Source<br />

DF<br />

Sum<br />

of<br />

Squares<br />

Mean<br />

Square<br />

F<br />

Value<br />

Pr<br />

F<br />

Model<br />

15<br />

4801.95000000<br />

320.13000000<br />

21.81<br />

0.0001<br />

Error<br />

64<br />

939.60000000<br />

14.68125000<br />

Corrected Total 79 5741.55000000<br />

R-Square C.V. Root MSE TIME Mean<br />

0.836351 11.90866 3.83161193 32.17500000<br />

Source<br />

DF<br />

Anova<br />

SS<br />

Mean<br />

Square<br />

F<br />

Value<br />

Pr<br />

F<br />

FACTORB<br />

3 1201.05000000 400.35000000 27.27<br />

0.0001<br />

FACTORA<br />

3 2992.45000000 997.48333333 67.94<br />

0.0001<br />

FACTORB*FACTORA 9 608.450000000 67.60555556 4.60 0.0001<br />

FIGURE 8.5.4 SAS ® output for analysis of Example 8.5.2.<br />

EXERCISES<br />

For Exercises 8.5.1 to 8.5.4, perform the analysis of variance, test appropriate hypotheses at the<br />

.05 level of significance, and determine the p value associated with each test.<br />

8.5.1. Uryu et al. (A-23) studied the effect of three different doses of troglitazone ðmMÞon neuro cell death.<br />

Cell death caused by stroke partially results from the accumulation of high concentrations of<br />

glutamate. The researchers wanted to determine if different doses of troglitazone (1.3, 4.5, and<br />

13:5 mM) and different ion forms ð and þÞ of LY294002, a PI3-kinase inhibitor, would give<br />

different levels of neuroprotection. Four rats were studied at each dose and ion level, and the measured<br />

variable is the percent of cell death as compared to glutamate. Therefore, a higher value implies<br />

less neuroprotection. The results are displayed in the table below.<br />

Percent Compared<br />

to Glutamate<br />

LY294002 vs þ LY294002<br />

Troglitazone<br />

Dose (mM)<br />

73.61 Negative 1.3<br />

130.69 Negative 1.3<br />

118.01 Negative 1.3<br />

140.20 Negative 1.3<br />

(Continued)

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