No. of Printed Pages: 4 IMSTL-OOllSll
I..'J POST GRADUATE DIPLOMA IN APPLIED STATISTICS (PGDAST) OJ Term-End Examination June, 2016
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L.... MSTL-001/S1 BASIC STATISTICS LAB SET-1
Time: 3 Hours Maximum Marks: 50
Note: Attempt any two questions.
Solve the questions in Microsoft Excel.
Use of Formulae and Statistical Tables Booklet for PGDAST is allowed.
Mention necessary steps, hypothesis, interpretation, etc.

1. The following data represents the electricity bills (in hundreds of Rs) during a particular month for a random sample of 50 three-bedroom apartments in New Delhi:
96 171 202 178 147 102 153 197 127 82
157 185 90 116 172 111 148 213 130 165
141 149 150 175 123 128 144 168 109 167
95 163 206 154 130 143 187 166 139 149
108 119 183 151 114 135 191 137 129 158

Form a continuous frequency distribution by computing suitable width.

Draw the histogram.

Form Cumulative and Relative frequency distributions.

A Local pizza restaurant and a branch of a National Chain are located across the street from a college campus. The local pizza restaurant advertises that it delivers to the dormitories faster than the National Chain. In order to examine whether this claim is valid, 10 pizzas from the Local pizza restaurant and 10 pizzas from the National Chain are ordered at different times. The delivery times (in minutes) are shown below:

Local Restaurant National Chain
16 22
11 15
15 18
16 15
17 20
18 19
14 17
21 19
13 16
20 24

At level of significance, is there any evidence that the

variances of the delivery times of the Local pizza restaurant and National Chain are equal

mean delivery time for the Local pizza restaurant is less than that for the National Chain Assume that the delivery times are normally distributed.


2. One of the major measures of the quality of service provided by any organization is the speed with which it responds to customer complaints. A large family-held departmental store selling furniture and flooring, including carpets, had undergone a major expansion in the past several years. In particular, the flooring department had expanded from 2 installation crews to an installation supervisor, a measurer, and 15 installation crews. A sample of 50 complaints concerning carpet installation was selected. The following data represents the number of days between the receipt of a complaint and the resolution of the complaint:

54,5,35,137,31,27,152,2,123,81,74,27,11,19,126, 110, 13, 10,5,27,4,52,30,22,36,26,20,23,33,68.

Compute the mean, median, first quartile and third quartile.

Compute interquartile range, variance, standard deviation and coefficient of variation.

Is the data skewed? If so, how?

A marketing manager of a company producing tyres was interested in knowing the comparative picture of the average life of various brands of tyres. An experiment was carried out in 4 cities in which the life of 4 brands of tyres (in thousands of kms) was estimated. The following data is collected:

City Brand
Brand 1 Brand 2 Brand 3 Brand 4
City 1 40 39 51 45
City 2 30 31 40 48
City 3 46 48 56 50
City 4 36 35 50 55

Perform suitable tests to check whether significant differences at level in tyres' mean life exist among the cities, and brands. If there are significant differences among cities or brands, carry out pairwise comparisons.

3. The following data represents the calories and fat (in grams) in 7 different types of iced coffee drinks

Coffee type: 1 2 3 4 5 6 7
Calories: 240 260 350 350 420 510 530
Fat: 08 3.5 22 20 16 22 19

Draw the box-plots separately for calories and fat data.

Nine contestants were rated by two experts in a cooking show for coffee making. A rating on a 7-point scale extremely unpleasant, 7 =extremely pleasing) is given for each of four characteristics taste, aroma, richness and acidity. The following data displays the summated ratings accumulated over all four characteristics:

Contestant Expert
X Y
A 24 26
B 27 27
C 19 22
D 24 27
E 22 25
F 26 27
G 27 26
H 25 27
I 22 23

Compute the rank correlation coefficient between the experts.