Page 207 - Engineering Mathematics Workbook_Final

Probability & Statistics

(a) 6 per hour (b) 10 per hour holders who main an average daily
balance more than Rs. 500 is _____.
(c) 12 per hour (d) 24 per hour
277. For a random variable
[GATE 2017 ME SESSION-II]
)
x
( x −   following normal
274. The arrival of customers over fixed distribution, the mean is  = 100 if
time intervals in a bank follow a the probability is P  for x  110.
=
poisson distribution with an average Then the probability of x laying

of 30 customers / hour. The between 90 and 110 i.e.,
probability that the time between P (90  x  110 ) and equal to
successive customer arrival is
between 1 and 3 m minutes is ____ (a) 1 2 (b) 1 
−
−
(correct to two decimal places).
−
(c) 1  /2 (d) 2
[GATE-2018 (ME-AFTERNOON
SESSION)] [GATE, PI : 2008]

275. Let X and X be two independent 278. Suppose X is a normal random
1 2
exponentially distributed random variable with mean 0 and variance 4.
variables with means 0.5 and 0.25, Then the mean of the absolute value
,
respectively. Then Y-min ( X X 2 ) of X is
1
is
1 2 2
(a) exponentially distributed with (a) 2 (b) 
mean 1/6

(b) exponentially distributed with 2 2 2
mean 2 (c)  (d) 

(c) normally distributed with mean ¾
[GATE 1999]
(d) normally distributed with mean
1/6 279. Which one of the following
statements is not true?
[GATE 2018 (ME-AFRTERNOON
SESSION)] (a) The measure of skewness is
dependent upon the amount of
NORMAL DISTRIBUTION
dispersion
276. A nationalized bank has found that

the daily balance available in its (b) In a symmetric distribution, the
savings accounts follows a normal values of mean, mode and median are
distribution with a mean of Rs. 500 the same
and a standard deviation of Rs. 50. (c) In a positively skewed
The percentage of savings account distribution, mean > median > mode

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