00:01
All right, that's a good question involving finding mean, median standard deviation in intercortel range.
00:07
And what i did was i typed the values for each manuel and gretchen into my statistical register in my tia 84 plus.
00:16
And you press the stat button and edit and in l1 or list one, i typed the values in for manuel, did the calculations, and did the same thing for gretchen.
00:27
And one thing to note, when i looked at the table that was given, your problem statement.
00:33
In the table there, gretchen's value for the standard deviation is given is 4 .69.
00:38
That's actually the sample standard deviation, and that is s -subscript x.
00:44
Okay, the other one, sigma subscript x, is a population standard deviation.
00:48
So i did notice that the problem is using the sample standard deviation.
00:55
Okay.
00:55
The other piece there is the interquartel range.
00:58
That's the difference in q3 and q1.
01:01
Q3 is the median of the upper half of the data.
01:04
Q1 is the median of the lower half of the data.
01:06
Remember when we're finding the median, we're looking for the middle value.
01:11
So if the data set has an odd number of values, we take the middle number.
01:15
If it's an even set of values, we take the average of the middle two values.
01:21
And then the last thing here at the bottom, just for, i think this formula is helpful to understand what standard deviation is.
01:29
And in a nutshell, what we're doing is taking the difference in each data value compared to the mean.
01:35
So, for example, underneath the square root symbol, we have in the first set of parentheses, x sub 1 minus x bar...