Question

(Attempt any four questions)
[40
11a
Question 5
In a GP the first term is 7, the last term is 448, and the sum is 989. Find
the common ratio and hence find the number of terms of the series.
(b) State the nature of the roots of the equation x2 – 3(x + 3) = 0 and
Hence solve it correct to two significant figures.
(C) Use step deviation method to find the mean of the given distribution.
Also state the modal class.
Marks
No. of students
11 - 20
21 - 30
31 - 40
41 - 50
51 - 60
61 - 70
71 - 80​

Answer 1

Answer:

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Answer 2

Answer:

a) GP in first term = 7

GP in last term = 448

7 × 448 = 3,136

Then its cutting and the answer will be 989

b) x2 - 3 ( x+3 ) = 0

= (0)2 - 3 ( 0 + 3 )

= -2 + 3

= - 1

c) 11 - 20 = 9

21 - 30 = 9

31 - 40 = 9

41 - 50 = 9

51 - 60=9

61 - 70 =9

71 - 80 = 9

all are same the mean of given distribution is 9

mean = 9