Description
TUTOR MARKED ASSIGNMENT
BSTM-161: Basic Statistical Methods
Course Code: BSTM-161
Assignment Code: BSTM-161/TMA/2026
Valid from 1st Jan, 2026 to 31st Dec, 2026
Maximum Marks: 100 Note: All questions are compulsory. Answer in your own words.
1.State whether the following statements are True or False and also give the reason in support of your answer. (2×5=10)
a) If Standard Deviation of the Variable X is 5, then the Standard Deviation of the Variable Y = 2X–3 will be 7.
b) Mean Deviation for a given data is least when calculated from the Median.
c) The Karl Pearson’s Correlation Coefficient between X and (a – X) is –1.
d) The Regression Coefficients byx and bxy of a data are found to be 1.2 and 0.8, respectively.
e) In Exclusive Method, Upper Limit of a class is included in the same class.
2.a) Find the missing information from the following data:
Section B:
3.a) The frequency distribution of the marks obtained by the 25 students each of the two sections is given as follows:
b) Mean and Standard Deviation of 18 observations are found to be 7 and 4, respectively. On observing the original data, it was found that observation 12 was miscopied as 21 in the calculations. Calculate correct Mean and Standard Deviation.
4.The equations of two Regression Lines are given as follows:
4x – 5y + 30 = 0
20x−9y – 107 = 0
Calculate (i) Regression Coefficients, byx and bxy; (ii) Correlation Coefficient r(x, y); (iii) Mean of X and Y; and (iv) the value of σy if σx = 3.
5.A Researcher collects the following information for two variables x and y:
n = 20, r = 0.5, Mean (x) = 15, Mean (y) = 20, σx = 4 and σy = 5
Later it was found that one pair of values (x, y) was wrongly taken as (16, 30) whereas the correct values were (26, 35). Find the correct value of r(x, y).
6.a) If A, B, C, D are constants, then show that the Coefficient of Correlation between (AX+B) and (CY+D) is numerically equal to that between X and Y.
b) A Statistician wanted to compare two Methods A and B of Teaching. He selected a random sample of 22 students. He grouped them into 11 pairs so that the students in pair have approximately equal scores on an intelligence test. In each pair one student was taught by Method A and the other by Method B and examined after the course. The marks obtained by both methods are given as:
Find the Spearman’s Rank Correlation Coefficient.
7.Fit an Exponential Curve of the form Y = abX to the following data:
X: 1 2 3 4 5 6 7 8
Y: 1.0 1.2 1.8 2.5 3.6 4.7 6.6 9.1
b) Calculate the first, second and third Quartiles for the following data:
Class: Below 30 30-40 40-50 50-60 60-70 70-80 80 and above
Frequency: 69 167 207 65 58 27 10
Also find the Quartile Deviation and Coefficient of Quartile Deviation.
Reviews
There are no reviews yet.