Stats tests

Question 1

what does a high and low standard deviation value mean

Answer 1

high = wider spread of values about the mean

low = most values close to mean

Question 2

standard deviation definition

Answer 2

a measure of how spread out the values are from the mean

Question 3

advantages of using standard deviation over the range

Answer 3

SD shows spread of data about the mean (range only gives difference between highest and lowest value)
SD reduces effect of anomalies (range includes anomalies)
SD can be used to indicate whether a difference between results is significant

Question 4

what is a hypothesis?

Answer 4

a statement about what you expect your results will show

Question 5

what hypothesis do you write at the start of a stat test?

Answer 5

the null hypothesis (no significant difference etc.)

Question 6

what value of p do we use to find the critical value

Answer 6

use the critical value at p = 0.05

Question 7

degrees of freedom in chi squared test

Answer 7

n-1

Question 8

when do you accept the null hypothesis

Answer 8

when the critical value is greater than the statistical value

Question 9

when do you reject the null hypothesis

Answer 9

when the critical value is lower than the statistical value

Question 10

what is the chi-squared test used for