Statistics · JEE Main previous year questions

2005 3 questions

1. Q372005 · 28 Apr 2005 · Shift 1

   A random variable $X$ has Poisson distribution with mean $2$. Then $P(X>1.5)$ equals :

   1. A.$\frac{2}{e^2}$
   2. B.$0$
   3. C.$1-\frac{3}{e^2}$
   4. D.$\frac{3}{e^2}$
   Show answer

   Answer: C

2. Q502005 · 28 Apr 2005 · Shift 1

   If in a frequency distribution, the mean and median are 21 and 22 respectively, then its mode is approximately :

   1. A.20.5
   2. B.22.0
   3. C.24.0
   4. D.25.5
   Show answer

   Answer: C

3. Q512005 · 28 Apr 2005 · Shift 1

   Let $x_1,x_2,\dots ,x_n$ be $n$ observations such that $$\sum x_i^2=400\text{ and }\sum x_i=80.$$ Then a possible value of $n$ among the following is

   1. A.$18$
   2. B.$15$
   3. C.$12$
   4. D.$9$
   Show answer

   Answer: A