00:01
Hi dead, in this problem the number of units sold in months is given in the table and we have to find the mean number of units sold and the standard deviation.
00:11
Firstly, we will use the formula for mean which is given as summation of xi divided by n.
00:21
In this case we have the number of units sold is equal to 94, 110, 86, 94 and 91.
00:30
So we find the sum of these that is 94 plus 10 plus 86 plus 94 plus 91 and divided by the total number of the values that is 5.
00:42
So it will be equal to 95 .0 on calculation.
00:47
So we write that the mean number of the mean number of units sold is equal to 95 and this is our number.
01:05
Answer for part a.
01:06
Now in the part b of this problem we are required to find the standard deviation.
01:13
So the standard deviation is given by the formula square root xi minus x bar whole square divided by n minus 1.
01:38
So in this problem we have square root the first value of x is 94 minus the mean that is 95.
01:48
Whole square plus 18010 minus mean that is 95 whole square plus 86 minus 95 whole square plus 94 minus 95 whole square plus finally we have 91 minus 95 whole square and this is divided by n minus 1 that is 5 minus 1 then on simply this will be equal to square root of 94 minus 95 whole square will be 1 plus 110 minus 95 is 15 so whole square is 225 plus 186 minus 95 whole square is 81...