Year 1 stats

- [ ] Single variable data, scatter diagrams & correlation, measures of central tendency & variation, standard deviation, outliers, coding NEED to add correlation and regression linear and exponential

Measures of location are

Single values that describe a position in a data set eg percentiles, maximum, mean

Measures of central tendency are

Values that describe the centre of the data eg mean, mode, median

Measures of spread are

To do with how the data is distributed eg range, standard deviation, IQ range

Symbol for mean on calculator

X with a line on top

How to find the position of the median for listed data

1) n/2

2) if a decimal round up, If a whole use halfway between this item and the next

When do you use linear interpolation

When finding a specific value that is in a class interval on a frequency table eg when finding the median

What is something to lookout for when doing linear interpolation

The class width is rounded so then need to use upper and lower limits

In grouped data what value do you use for the median

N/2

(AND JUST LEAVE IT LIKE THAT)

Describe variance in words

Average squared distance from the mean

Or the mean of the squares minus the square of the mean (msmsm)

When coding what effect does addiction and subtraction have on variance

No effect

When coding what effect does multiplication by k have on variance

Multiplies the variance by k²

When coding what does any linear transformation do to the mean eg y = mx+c

It transforms the mean in the same way

How to calculate statistics of data on a calculator for 1 variable

Enter numbers into list 1

F2 - calc

F1 - 1-VAR

Find the mean using calculator

List 1 - enter the midpoint of each hight group

List 2 - enter the frequencies

F2 - Calc

F6 - set

1 var X list : list b1

1 Var freq list 2

F1 - 1 var

Mean = 1.16875