A random sample of 20 people is classified in the following table according to their ages : 

Age	Frequency
15-25	2
25-35	4
35-45	6
45-55	5
55-65	3

What is the mean age of this group of people ?

• 41.0

• 41.5

• 42.0

• 42.5

If the covariance between x and y is 30, variance of x is 25 and variance of y is 144, then what is the correlation coefficient ?

• 0.4

• 0.5

• 0.6

• 0.7

A car travels first 60 km at a speed of 3v km/hr and travels next 60 km at 2v km/hr. What is the average speed of the car?

• 2.5v km/hr

• 2.4v km/hr

• 2.2v km/hr

• 2.1v km/hr

If V is the variance and M is the mean of first 15 natural numbers, then what is V + M² equal to ?

• $\frac{124}{3}$

• $\frac{148}{3}$

• $\frac{248}{3}$

• $\frac{124}{9}$

If the range of a set of observations on a variable X is known to be 25 and if Y = 40 + 3X, then what is the range of the set of corresponding observations on Y ?

• 25

• 40

• 75

• 115

46.

Mean of 100 observations is 50 and standard deviation is 10. If 5 is added to each observation, then what will be the new mean and new standard deviation respectively ?

• 50, 10

• 50, 15

• 55, 10

• 55, 15

Consider the following discrete frequency distribution:

x	1	2	3	4	5	6	7	8
f	3	15	45	57	50	36	25	9

What is the value of median of the distribution ?

• 4

• 5

• 6

• 7

The mean of 5 observations is 4.4 and variance is 8.24. If three of the five observations are 1, 2 and 6, then what are the other two observations ?

• 9, 16

• 9. 4

• 81, 16

• 81, 4

The class marks in a frequency table are given to be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50. The class limits of the first five classes are

• 3-7, 7-13, 13-17, 17-23, 23-27

• 2.5-7.5, 7.5-12.5, 12.5-17.5, 17.5-22.5, 22.5-27.5

• 1.5-8.5, 8.5-11.5, 11.5-18.5, 18.5-21.5, 21.5-28.5

• 2-8, 8-12, 12-18, 18-22, 22-2

The median of the observations 22, 24, 33, 37, x + 1, x + 3, 46, 47, 57, 58 in ascending order is 42. What are the values of 5^th and 6^th observations respectively ?

• 42, 45

• 41, 43

• 43, 46

• 40, 40