Respuesta :
mean = 60 / 4 = 15
13 - 15 = -2
17 - 15 = 2
9 - 15 = -6
21 - 15 = 6
Total of squares = 4 + 4 + 36 + 36 = 80
because this is a sample we divide this by n - 1 ( = 3)
Standard deviation = sqrt (80/3) = 5.16 answer
13 - 15 = -2
17 - 15 = 2
9 - 15 = -6
21 - 15 = 6
Total of squares = 4 + 4 + 36 + 36 = 80
because this is a sample we divide this by n - 1 ( = 3)
Standard deviation = sqrt (80/3) = 5.16 answer
Answer:
standard deviation=4.47
Step-by-step explanation:
We have to find the standard deviation of the data set:
13 17 9 21
Now we calculate the mean of the data .
We know that mean is the average of the data values and is calculated as:
[tex]Mean=\dfrac{13+17+9+21}{4}\\ \\Mean=\dfrac{60}{4}\\\\Mean=15[/tex]
Now we find the difference of each data point from the mean as:
Deviation:
13-15=-2
17-15=2
9-15=-6
21-15=6
Now we have to square the above deviations we obtain:
4 4 36 36
now we calculate the mean of the above sets:
[tex]variance=\dfrac{4+4+36+36}{4}\\ \\Variance=\dfrac{80}{4}\\\\Variance=20[/tex]
now standard deviation is the positive square root of variance
so, standard deviation=√(20)=4.47