Statistical Tests + food tests

Question 1

What does a T test measure

Answer 1

Investigate difference between 2 means

Question 2

What does a correlation coefficient test for

Answer 2

Investigate association between 2 measurements

Question 3

What does Chi squared test for and steps

Answer 3

Investigating difference between frequencies

Calculate expected values

Calculate chi-squared

Find the critical value using degrees of freedom

Accept or reject the null hypothesis

Question 4

Test for lipids

Answer 4

Emulsion test
- add equal amounts of ethanol and water to sample
- if lipid present = white emulsion forms

Question 5

Test for proteins

Answer 5

Biuret reagent
- add equal volumes of NaOH + sample
- add drops of copper sulfate
- if protein present blue = to purple

Question 6

Degrees of freedom

Answer 6

Number of categories - 1
n-1

Question 7

In a Chi-Squared test are the results statistically significant if the value is greater than the critical value

Answer 7

yes
reject null hypothesis
results are not due to chance