# z-score

For z-score calculation, please enter numerical data separated with comma (or space, tab, semicolon, or newline). For example: 470.8 229.3 322.8 724.9 236.4 908.2 -440.3 294.4 459.1 440.4 947.4 493.0 707.8### Z-score

Z-score (or standard score) is the transform of items x via the formula:$z=σx−μ $

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 a frequency table?

Simple. First-type data elements (separated by spaces or commas, etc.), then type f: and further write the frequency of each data item. Each element must have a defined frequency that count 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 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 a cumulative frequency table?

Similar to a frequency table, but instead f: type cf: in the 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.

## Practice problems from statistics:

- Harmonic HM example

Find the harmonic mean of 4 and 8. - Median and modus

Radka made 50 throws with a dice. The table saw fit individual dice's wall frequency: Wall Number: 1 2 3 4 5 6 frequency: 8 7 5 11 6 13 Calculate the modus and median of the wall numbers that Radka fell. - 75th percentile (quartille Q3)

Find 75th percentile for 30,42,42,46,46,46,50,50,54 - The data

The data set represents the number of cars in a town given a speeding ticket each day for ten days. 2 4 5 5 7 7 8 8 8 12 What is the IQR? - Increase the mean

To which number should the number 4 be changed between the numbers 4,5,7, 1,0,9,7,8, -3,5 to increase these numbers' arithmetic mean by 1.25? - The size 2

The size of pants sold during one business day in a department store are 32, 38, 34, 42, 36, 34, 40, 44, 32, and 34. Find the average size of the pants sold. - 45 percentile

Given the following data 11 15 24 33 10 35 23 25 40 What is P45? - Average

If the average(arithmetic mean) of three numbers x,y,z is 50. What is the average of there numbers (3x +10), (3y +10), (3z+10) ? - Dataset:

Dataset: 35 22 18 54 22 46 28 31 43 22 14 17 25 19 33 14. 1 Group the data into a grouped distribution using 6 classes of equal width. 2. Determine the mean, median, and mode using the raw data. 3. Draw an Ogive curve corresponding to the data and use it - Centimeters 66264

The average height of the basketball team's primary five players is 196 cm. The underscore player is 216 cm tall. What is the average height of the remaining four players in centimeters? - Marketing

Year; money spent on advertising; profit 2008 2 12 2009 5 20 2010 7 25 2011 11 26 2012 15 40 1. draw a scatter diagram depicting the data. 2. calculate the Pearson's correlation coefficient. 3. determine the linear regression equation.

more math problems »