Assuming that am supposed to calculate the the mean absolute deviation of
1,2,3,4,5,6,7
mean absolute deviation is calculated by first calculating the mean;
(1+2+3+4+5+6+7) =28/7
= 4
Then, find the absolute value (the difference between each value in the data and the mean) (x-μ)
= -3,-2,-1,0,1,2,3
Absolute values= 3,2,1,0,1,2,3
Then we find the mean of the values,
3+2+1+0+1+2+3 = 12
= 12/7
= 1.7143
Therefore, the mean is 4, and the Mean absolute deviation is 1.7143
Answer:

Step-by-step explanation:
Given
Let the total probability be 1
Probability that Brian wins a raffle = n/n+2
Probability that Brian does not win a raffle = 1 - Probability that Brian wins a raffle
Probability that Brian does not win a raffle = 1 - (n/n+2)
Probability that Brian does not win a raffle = 
Probability that Brian does not win a raffle = 
Hence required fraction is
The answer is 2b+2 hope this will help