Question

We need to use R

1) By carefully going through patient records, you determine relative exposure by Unit and by patient as shown below:

Patient:   1,     2,    3,   4,   5,   6,      7,     8,      9,   10

Unit A:   84, 109, 57, 91, 80, 81, 109, 107,   98, 111

Unit B:   86, 104, 68, 95, 83, 87, 118, 114, 108, 116

1. Create an appropriate chart to visualize the data
2. What statistical test is appropriate to determine whether the exposures from the two units differ significantly

c. What can you conclude from the statistical analysis?

Answer 1

Result:

Create an appropriate chart to visualize the data

Box plot is used to present the data.

What statistical test is appropriate to determine whether the exposures from the two units differ significantly

test appropriate here is Independent sample t test ( two sided).

What can you conclude from the statistical analysis?

Obtained test statistic t = -0.67987, df = 18, p-value = 0.5052 which is > 0.05 level of significance. Ho is not rejected.

we conclude that the exposures from the two units not differ significantly.

R code:

A=c(84, 109, 57, 91, 80, 81, 109, 107, 98, 111)

B=c( 86, 104, 68, 95, 83, 87, 118, 114, 108, 116)

boxplot(A,B,names=(c("Unit A","Unit B")))

t.test(A,B, var.equal = TRUE, conf.level=.95)

R output:

t.test(A,B, var.equal = TRUE, conf.level=.95)

        Two Sample t-test

data: A and B

t = -0.67987, df = 18, p-value = 0.5052

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

95 percent confidence interval:

-21.26896 10.86896

sample estimates:

mean of x mean of y

     92.7      97.9