Please also mark your answers on this examination paper and bring it home.
NATIONAL UNIVERSITY OF SINGAPORE
Department of Statistics and Applied Probability
Academic Year 2013/2014, Semester I
ST1131 Introduction to Statistics
Mid-Term Examination
4 October 2013
1. Which of the following distributions is symmetric?
(A) Normal distribution.
(B) A right skewed distribution.
(C) A left skewed distribution with an outlier.
(D) A left skewed distribution with two outliers.
(E) All of the above.

2. Fifty residents were sampled randomly from a village in Malaysia. Their mean and
median blood cholesterol levels were found to be 192 mg/dL and 203 mg/dL respec-
tively. Which of the following statements is the most appropriate for describing the
distribution of blood cholesterol levels of residents in the village?

3. Which of he following statements is always true about least-squares regression?

1

4. A normal probability plot of the heights (in cm) of a random sample of children is
shown below. Which of the following statements is the most appropriate?