maths, stats and equations

Question 1

what is chi squared used for?

Answer 1

for categorical data (frequencies etc)

Question 2

what is a null hypothesis?

Answer 2

no significant difference

Question 3

what is (student) t test used for? (paired/unpaired)

Answer 3

comparing means of 2 sets of data

Question 4

what is spearman’s rank/ correlation coefficient used for?

Answer 4

examining association between 2 sets of data

Question 5

What statistical test is used to compare means between two groups?

Answer 5

Student’s t-test

Question 6

What statistical test is used to see if there is an association between two categories?

Answer 6

Chi-squared test

Question 7

What statistical test is used to assess correlation between two variables?

Answer 7

Spearman’s rank correlation coefficient

Question 8

What does a p-value < 0.05 indicate?

Answer 8

The result is statistically significant; there’s less than a 5% probability the result is due to chance.

Question 9

(“Q: What is the formula for the mean?”

Answer 9

“A: Mean = Σx / n”)

Question 10

(“Q: What is the formula for standard deviation?”

Answer 10

“A: √(Σ(x−x̄)² / (n−1))”)

Question 11

(“Q: What does standard deviation measure?”

Answer 11

“A: The spread of data around the mean.”)

Question 12

(“Q: What does a small standard deviation indicate?”

Answer 12

“A: The data points are close to the mean.”)

Question 13

(“Q: What is the formula for percentage change?”

Answer 13

“A: ((final value - initial value) / initial value) × 100”)

Question 14

(“Q: What is the formula for surface area of a sphere?”

Answer 14

4πr²

Question 15

(“Q: What is the formula for volume of a sphere?”

Answer 15

(4/3)πr³

Question 16

(“Q: What is the formula for surface area to volume ratio?”

Answer 16

“SA:V = surface area / volume

Question 17

(“Q: How is the rate of reaction calculated?”

Answer 17

Change in quantity / time

Question 18

(“Q: How is magnification calculated?”

Answer 18

Magnification = Image size / actual size

Question 19

(“What is the formula triangle for magnification?

Answer 19

I = A × M

Question 20

(“Q: What is the formula for uncertainty?”

Answer 20

“A: Uncertainty = (range / 2) or based on instrument precision”)

Question 21

(“Q: How do you calculate percentage error?”

Answer 21

“A: (Uncertainty / measured value) × 100”)

Question 22

(“Q: What is the formula for index of diversity?”

Answer 22

“A: D = N(N−1) / Σn(n−1)”)

Question 23

(“Q: What does N represent in the index of diversity?”

Answer 23

“A: Total number of organisms of all species”)

Question 24

(“Q: What does n represent in the index of diversity?”

Answer 24

“A: Number of individuals of each species”)

Question 25

("Q: What is the formula for Q10?"

Answer 25

"A: Q10 = (rate at higher temp) / (rate at lower temp)")

Question 26

("Q: Convert mm to µm"

Answer 26

"A: Multiply by 1000")

Question 27

("Q: Convert cm³ to mm³"

Answer 27

"A: Multiply by 1000")

Question 28

("Q: Convert µm to nm"

Answer 28

"A: Multiply by 1000")

Question 29

("Q: Convert µm to mm"

Answer 29

"A: Divide by 1000")

Question 30

("Q: What is 1 cm³ in mm³?"

Answer 30

"A: 1000 mm³")

Question 31

("Q: What is 1 mm in µm?"

Answer 31

"A: 1000 µm")

Question 32

("Q: What is 1 µm in nm?"

Answer 32

"A: 1000 nm")

Question 33

("Q: What does the gradient of a graph represent?"

Answer 33

"A: Rate of change")

Question 34

("Q: How is the gradient calculated?"

Answer 34

"A: Change in y / change in x")

Question 35

("Q: What is an anomaly?"

Answer 35

"A: A result that does not fit the pattern or is far from the others")

Question 36

("Q: Why is a line of best fit used?"

Answer 36

"A: To show the trend of the data")