Question

Thirty nine women with a diagnosis of inoperable or metastatic breast cancer have been followed-up for a number of years, while under continuous treatment with a medication called trastzuzumab. The time (in months) each patient remained in remission was recorded. Remission is is a decrease or disappearance of signs and symptoms of cancer. Below is the data.

50 74 35 39 21 37 27 35 30 35 26 38 34 34 26 41 61 33 33 26 25 41 35 34 44 33 60 61 42 30 80 31 24 49 26 31 28 41 37.

1. Are there any outliers in the sample? If so, indicate their values.

2. Compute the 45-th percentile of the remission time.

3. Find a 97% confidence interval for the average remission time.

Answer 1

R-code :

> x<-c(50, 74, 35, 39, 21, 37, 27, 35, 30, 35, 26, 38, 34, 34, 26, 41, 61, 33, 33, 26, 25, 41 ,35 ,34, 44, 33, 60 ,61 ,42, 30, 80, 31 ,24, 49 ,26, 31, 28, 41 ,37)
> boxplot(x)
> summary(x)
Min. 1st Qu. Median Mean 3rd Qu. Max.
21.00 30.00 35.00 38.13 41.00 80.00
> 41+1.5*(41-30)
[1] 57.5
> x[x>57.5]
[1] 74 61 60 61 80