scientific method test

Question 1

state the definition of the three variables of normal tendency

Answer 1

mean = average
median: mid point
mode: most common number

Question 2

3 measures of variability and what the are

Answer 2

1. variance: distance between data points & mean
2. SD: how far apart numbers are in your sample
3. range

Question 3

what is SE

Answer 3

how accurately results are compared to population

Question 4

what happens when S and SD are increased

Answer 4

data points are farther apart in your sample = higher variability = more outliers = less certain that the mean represents the true average of the sample

Question 5

what happens when the SE is higher

Answer 5

less certain that sample mean accurately represent that of the population

Question 6

what is alpha

Answer 6

0.05 0r 5% — estimate of the probability that results occurred due to statistical accident (chance)

Question 7

p-value < a

Answer 7

results are statistically significant — data support alternate hypothesis

Question 8

how does sample size affect variability

Answer 8

larger sample size = lower variability
more reliable data — outliers are less significant in large groups

Question 9

when not to use t-test

Answer 9

• when the data comes from the same individual
• when there’s less or more than 2 groups
• no averages (or identical averages)

Question 10

what happens when you have identical averages

Answer 10

the t-cal is 0 which gives a p value of 1 so the null is correct

Question 11

t-cal < t-crit

Answer 11

fail to reject the null hypothesis — there is no significant difference

Question 12

biological replicate

Answer 12

1 individual living organisme per replicate