Megoldás - Statisztika

Divide the sum by the number of terms:

Sum
$$845$$
Number of terms
$$3$$

$$x̄=\frac{845}{3}=281,667$$

The mean equals $$281,667$$

Arrange the numbers in ascending order:
125,320,400

Count the number of terms:
There are (3) terms

Because there is an odd number of terms, the middle term is the median:
125,320 400

The median equals 320

To find the range, subtract the lowest value from the highest value.

The highest value equals 400
The lowest value equals 125

$$400-125=275$$

The range equals 275

To find the sample variance, find the difference between each term and the mean, square the results, add together all of the squared results, and divide the sum by the number of terms minus 1.

The mean equals 281,667

To get the squared differences, subtract the mean from each term and square the result:

To get the sample variance, add together the squared differences and divide their sum by the number of terms minus 1

Sum:
$$24544 444+14002 778+1469 444=40016 666$$
Number of terms:
$$3$$
Number of terms minus 1:
2

Variance:
$$\frac{40016 666}{2}=20008 333$$

The sample variance ($$s^2$$) equals 20008,333

The standard deviation of the sample equals the square root of the sample variance. This is why the variance is usually represented by a squared variable.

Variance: $$s^2=20008,333$$

Find the square root:
$$s=\sqrt{\left(20008,333\right)}=141451$$

The standard deviation ($$s$$) equals 141 451