Answer:
Step-by-step explanation:
Discussion
This should be answered with the mean. The lower the mean, the lower the score it took to get the mean. So B is the answer.
The square of a binomial expands as follows:
Expanding all the binomials, we have
Sum like terms:
Simplify terms appearing on both sides:
Move all terms involving k to the left and all numbers to the right:
Divide both sides by -20:
Answer:
Step-by-step explanation:
Given are 3 data sets with values as:
(i) 8 9 10 11 12 ... Mean =10
(ii) 7 9 10 11 13 ... Mean =10
(iii) 7 8 10 12 13 ... Mean =10
We see that data set shows mean deviations as
(i) -2 -1 0 1 2
(ii) -3 -1 0 1 3
(iii) -3 -2 0 2 3
Since variance is the square of std deviation, we find that std deviation is larger when variance is larger.
Variance is the sum of squares of (x-mean). Whenever x-mean increases variance increases and also std deviation.
Hence we find that without calculations also (i) has least std dev followed by (ii) and then (iii)
(i) (ii) (iii) is the order.
b) Between (i) and (ii) we find that 3 entries are the same and 2 entries differ thus increasing square by 9-4 twice. But between (ii) and (iii) we find that
increase in square value would be 4-1 twice. Obviously the latter is less.
Answer:
B,C,D are equivalent to 4^-3
