00:01
Hello students, we have given the scores of 19 students on the math test.
00:07
So sample size n is equal to 19, which is the odd number.
00:11
Then by using this data set, we have to calculate the mean median standard deviation then first quartiles 37th percentile 63rd percentile and 55th percentile.
00:25
So first to calculate the mean we know the formula for the mean is that is x bar which is equal to summation of x divided by n.
00:39
So now this is equal to 8 plus 10 plus 8 plus this is up to 16 plus 15 and divide by the total number of observations that is 19.
00:53
So this is equal to 13 .4737 then we have to calculate the median.
01:02
So to find the median first arrange the data arrange the given data in an ascending order ascending order.
01:21
Now we have n that is sample size which is equal to 19, which is the odd number and when n is odd then the formula for the median is equal to n plus 1 by tooth observation, which is equal to 19 plus 1 divide by tooth observation and that is equal to 10th observation.
01:51
So now after arranging the data in the ascending order, we will get the 10th observation is equal to 14.
01:58
So therefore median is equal to 14.
02:01
Then next we have to calculate the standard deviation and the formula for the standard deviation is standard deviation is equal to summation of x minus x bar bracket square divide by n minus 1 and this whole term is inside the square root sign.
02:20
So we have already calculated the sample mean that is x bar.
02:25
So by using that value we will get the standard deviation is equal to 1 upon n minus 1 that is 18 into bracket 8 minus 13 .4737 bracket square plus this is up to 15 minus 13 .4737 bracket square and this whole term is inside the square root sign.
02:52
So this is equal to 4 .0875.
02:58
This is the standard deviation.
03:00
Then we have to calculate the first quartiles that is q1 and the formula for q1 is q1 is equal to n plus 1 divide by fourth observation.
03:14
So here n is equal to 19...