Statistical Tests

Question 1

What is a sample?

Answer 1

A portion of the population being studied. (subset)

Question 2

Process of obtaining sample from the population

Answer 2

Sampling

Question 3

Differences between sample and population

Answer 3

Sample error. Frequency distribution of different samples AND the original population are not the same.

Question 4

Frequency distribution

Answer 4

Distribution of certain characteristics in a sample
Eg colour of jellybabies

Question 5

What type of test can be used to show that results are not or are due to sample error?

Answer 5

Chi squared - not just a chance result/due to sample error. Something of biological interest is going on

Question 6

Formula for calculating standard error

Answer 6

Sy = s / √n

s=standard deviation
n=sample size

Question 7

Confidence interval

Answer 7

+/- Sy
A range of values that is likely to include a population value

Question 8

Lower confidence limit

Answer 8

mean - tSy
degrees of freedom for t = n -1

Question 8

Upper confidence limit

Answer 8

mean + tSy
degrees of freedom for t = n -1

Question 9

95% confidence is

Answer 9

0.05 critical significance level

Question 10

Finding t for the confidence limit

Answer 10

Find critical significance level using % level of confidence
Degrees of freedom = n - 1

Question 11

Calculating Sample Varience

Answer 11

Square of Standard deviation

Question 12

When can varience be used?

Answer 12

When the data is taken from an entire population

Question 12

Process of finding variance

Answer 12

Sum of the difference between each of the data points and the mean squared. Take the average of that.

Question 13

Standard error of the mean

Answer 13

SE/SEM = SD/√n