Probability and Statistics Mid - I, September - 2010

1.If A and B are independent events and P (A ) = 23 and P (B) = 35 then ()cPAB∪ = ...... [ ]
  • 1/5
  • 4/15
  • 2/7
  • 1/3
Answer: B
2.If X1 and X2 are two independent random variables such that mean of X1 is 4 and that of X2 is 2 then E(2X1 3X2 2) =
  • 14
  • 10
  • 16
  • 24
Answer: C
3.A coin is tossed 4 times p (1) = .25, then p ( x = 2) = ________
  • 1/8
  • 3/8
  • 5/8
  • 7/8
Answer: B
4.Two samples of sizes 200 and 300 and variances 100 and 144 are taken. The standard error for is
  • .99
  • .79
  • .59
  • .69
Answer: A
5.If P = .75 maximum error with 95% confidence is .06 then the sample size is
  • 185
  • 250
  • 200
  • 150
Answer: C
6.The probability of getting two variables un equal when we throw two dice is ________
  • 1/6
  • 1/3
  • 1/12
  • 5/6
Answer: D
7.Mean of Binomial distribution is 6 and variance is 2 mode = .__________
  • 5
  • 6
  • 8
  • 9
Answer: B
8.If n = 169. The variance of the population is 25 and x = 50 then 99% confidence interval for is .......................
  • (42, 44)
  • (49, 51)
  • (36, 38)
  • (24, 26)
Answer: B
9.If the variance is 12 and n=150,then the Maximum error with 90% confidence is
  • .2189
  • .4653
  • .7231
  • .3451
Answer: B
10.Among 100 students in a class, 60 people use ball pens. With 95% confidence, the maximum error for true proportion is ..............
  • 1.23
  • .02
  • .03
  • .05
Answer: A
11.If X is a poisson variate such that p (x = 2) = .27 and p (x = 3) = .18 then μ= ________
Answer: 2
12.The standard deviaAations of two samples of lenghs 50 and 75 are 4 and 5 respectively, then the
Maximum error with 99% confidence is _______________
Answer: 2.0854
13.If the true proportion , the maximum error with .95 probability is .02. The sample size is _________________
Answer: 2134
14.Among 100 students in a class, 60 people use ball pens. With 95% confidence, the maximum error for true proportion is ______________
Answer: 1.23
15.If A and B is mutually exclusive events then ()ccPAB�� = __________
Answer: 1
16.A coin is tossed n times the probability at x = 2 = 3/8 and probability at x = 3 = 1/4 then n = ______
Answer: 4
17.If the X is poisson variate p ( x = 1) = .3679, p (x = 2) = .184 then � = ________
Answer: 1
18.If the maximum error with 99% confidence is .06 and σ = 1 then size of the sample is _____
Answer: 1849
19.If the variance is 6.25, n=90 and the mean of the population is 40 then the 95% confidence interval is _____________
Answer: 39.4835, 40.5165
20.If P = .75 maximum error with 95% confidence is .06 then the sample size is _______________
Answer: 200