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do this in R (using R project) Proteinuria, the presence of excess protein in ur

ID: 3267640 • Letter: D

Question

do this in R (using R project)

Proteinuria, the presence of excess protein in urine, is a symptom of renal (kidney) distress among diabetics. Taguma et al. (1985) studied the effects of captopril for treating proteinuria in diabetics. Urinary protein was measured for 12 patients before and after eight weeks of captopril therapy. The amounts of urinary protein (in g/24 hrs) before and after therapy are shown in the following table. What can you conclude about the effect of captopril? Consider using parametric or nonparametric methods and analyzing the data on the original scale or on a log scale.

Explanation / Answer

Answer:

R code:

# paired t-test

x1<-c(24.6,17.0,16.0,10.4,8.2,7.9,8.2,7.9,5.8,5.4,5.1,4.7)

x2<-c(10.1,5.7,5.6,3.4,6.5,0.7,6.5,0.7,6.1,4.7,2.0,2.9)

t.test(x1,x2,paired=TRUE)

R output:

# paired t-test

> x1<-c(24.6,17.0,16.0,10.4,8.2,7.9,8.2,7.9,5.8,5.4,5.1,4.7)

> x2<-c(10.1,5.7,5.6,3.4,6.5,0.7,6.5,0.7,6.1,4.7,2.0,2.9)

> t.test(x1,x2,paired=TRUE)

        Paired t-test

data: x1 and x2

t = 4.0012, df = 11, p-value = 0.002082

alternative hypothesis: true difference in means is not equal to 0

95 percent confidence interval:

2.485818 8.564182

sample estimates:

mean of the differences

                  5.525

Calculated t=4.0012, P=0.002082 which is < 0.05 level.

Ho is rejected.

We conclude that there is significant effect of captopril therapy.