# STA301 Statistics and Probability Assignment 2 Solution Fall 2012

Question 1:                                                                                                                        (Marks: 3+5=8)

a)      The fourth mean moment of a symmetric distribution is 243. What would be the value of the standard deviation in order that the distribution may be meso-kurtic?

b)      Two candidates X and Y at the B.A (Hons.) Examination obtained the following data.

 Candidate X Candidate Y = 43.2 = 20.5 S.D = 24.25 S.D = 15.6

Which of the candidate showed a more consistent performance?

Question 2:                                                                                                             (Marks: 2+5=7)

1. If coefficient of skewness = 0, then what would you say about the shape of the distribution?
2. The following data were computed from personnel records of a manufacturing firm:

X = Number of years of service

Y = weekly wage rate

n = 23; ∑X = 2433; ∑Y = 4254, ∑  = 281019;  = 841786 and = 482788

If the correlation coefficient indicates that there does exist a relationship between X and Y,                                    compute the least squares line of regression Y = a + b X.
Solution: