Given:
The sum of two terms of GP is 6 and that of first four terms is 
To find:
The sum of first six terms.
Solution:
We have,


Sum of first n terms of a GP is
...(i)
Putting n=2, we get


...(ii)
Putting n=4, we get



(Using (ii))
Divide both sides by 6.
Taking square root on both sides, we get

Case 1: If r is positive, then using (ii) we get
The sum of first 6 terms is




Case 2: If r is negative, then using (ii) we get
The sum of first 6 terms is




Therefore, the sum of the first six terms is 7.875.
Hi there!
The Eqn. is :-
1.5 (x + 4) - 3 = 4.5 (x - 2)
1.5x + 6 - 3 = 4.5x - 9
Combining the like terms :-
1.5x - 4.5x = - 9 - 6 + 3
- 3x = - 15 + 3
- 3x = - 12
x =

x = 4
Hence, the required answer is → x = 4
~ Hope it helps!
1. Mean.

2. <span>Standard deviation.
First we have to square each value and calculate the mean of that squares:

so the variance:

and the standard deviation:

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The brocoli would cost 6 dollars.