Page 200 - Engineering Mathematics Workbook_Final

Probability & Statistics

224. Marks obtained by 100 students in an 227. The standard deviation of liner

examination are given in the table: dimensions P and Q are 3 m and
4 m respectively. When assembled,

Marks Number of
S.No the standard deviation (in m
obtained students ) of the
1 25 20 resulting linear dimension (P+Q) is
2 30 20 _____.
3 35 40
4 40 20 [GATE-2017 ME SESSION-II]
What would be the mean, median and
mode of the marks obtained by the 228. The following sequence of numbers
students? is arranged in increasing order : 1, x,
(a) Mean 33; Median 35; Mode 40 x, x, y, y, 9, 16, 18. Given that the
mean and median are equal, and are
(b) Mean 35; Median 32; Mode 40
also equal to twice the mode, the
(c) Mean 33; Median 35; Mode 35 value of y is

(d) Mean 35; Median 32; Mode 35 (a) 5 (b) 6

[GATE-2014 (PI-SET 1)] (c) 7 (d) 8

225. The spot speed (expressed in km/hr) [GATE-2017 (CH)]
observed at a road section are 66, 62,
45, 79, 32, 51, 56, 60, 53 and 49. The DISCRETE RANDOM VARIABLE
median speed expressed in km/hr is 229. The mean of squares of first 23
_____. natural number is ______.

[Note answer with one decimal 230. A random variate has the following
accuracy] distribution:

[GATE-2016 (CE-SET 2)] x : 0 1 2 3 4 5 6 7

2
p x 2k 2k 3k k 2 2k 2 7k + k
( ) : 0 k
226. A sample of 15 data is as follows 17,
18, 17, 17, 13, 18, 5, 5, 6, 7, 8, 9 20,
17, 3. The mode of the data is The value of k is _____.

(a) 4 (b) 13 231. A six-face fair dice is rolled a large

number of times. The mean value of
(c) 17 (d) 20
the outcomes is ____.
[GATE 2017 ME SESSION-II]
[GATE 2017]

198