Topic 7 (statistics)

Question 1

hypothesis

Answer 1

statement/idea made about the value of a population parameter
-test a hypothesis through an experiment or from taking a sample of population

Question 2

test statistic

Answer 2

result of experiment or statistic calculated from the sample

Question 3

null hypothesis

Answer 3

H0
default position i.e nothing is biased nothing changes or nothing works
assume to be correct/true unless proved otherwise

Question 4

alternative hypothesis

Answer 4

H1
states there has been a change
assumption is shown to be wrong

Question 5

one tailed test

Answer 5

states there will be a change in a specified direction

H1: p<0.5 or H1: p>0.5

Question 6

two tailed test

Answer 6

states that there has been a change but doesnt specify direction
H1: p doesnt equal 0.5

Question 7

significance level

Answer 7

• consider how likely the observed value of the test statistic was to occur
• probability level at which you would reject the null hypothesis
• if less than a given threshold called a significance level = can reject null hypothesis
• if not there is not sufficient evidence to reject hypothesis

typical significance levels 10&, 5% or 1%

Question 8

critical region

Answer 8

region of probability distribution which if test statistic falls within it would cause you to reject the null hypothesis

-set of values which can lead to rejecting the null hypothesis

Question 9

critical value

Answer 9

first value to fall inside of the critical region

Question 10

p value

Answer 10

probability of the observed value or more extreme
two tailed you double it as you have split the significance level in half therefore need to double p-value to bring it back up

Question 11

observed value

Answer 11

lower than expected value P(X< or equal to x) = lower tail

higher than expected value P(X> or equal to x) = upper tail