# z-score

For calculation z-score enter numerical data separated with comma (or space, tab, semicolon, or newline). For example: 917.7 958.8 912.5 951.4 301.6 510.1 146.9 971.0 189.2 588.6 -377.3 -719.0 416.8### Z-score

Z-score (or standard score) is transform of items x via formula:$z = \dfrac{ x- \mu }{ \sigma}$

where:

μ is the mean of the population;

σ is the standard deviation of the population.

The absolute value of z represents the distance between the raw score and the population mean in units of the standard deviation. z is negative when the raw score is below the mean, positive when above.

### How to enter data as frequency table?

Simple. First-type data elements (separated by spaces or commas etc) then type f: and further write frequency of each data item. Each element must have defined frequency that number of numbers before and after symbol f: must be equal. For example:1.1 2.5 3.99

f: 5 10 15

### How to enter grouped data?

Grouped data are data formed by aggregating individual data into groups, so that a frequency distribution of these groups serves as a convenient means of summarizing or analyzing the data.group | frequency |

10-20 | 5 |

20-30 | 10 |

30-40 | 15 |

10-20 20-30 30-40

f: 5 10 15

### How to enter data as cumulative frequency table?

Similar as frequency table, but instead f: type cf: in second line. For example:10 20 30 40 50 60 70 80

cf: 5 13 20 32 60 80 90 100

The cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors. The last value will always be equal to the total for all observations, since all frequencies will already have been added to the previous total.