Data-based and statistical reasoning

Question 1

normal distribution

Answer 1

symmetrical, mean/median/mode are all the same

Question 2

standard distribution

Answer 2

normal distribution with a mean of zero and standard deviation of one

Question 3

skewed distribution

Answer 3

have differences in mean/median/mode
direction of skew is the direction of the tail (values closest to zero)
- skewed meanmedian

Question 4

Bimodal distribution

Answer 4

multiple peaks

Question 5

range

Answer 5

difference between largest and smallest values

Question 6

interquartile range

Answer 6

third quartile - first quartile
third quartile = middle value between the median and the highest value
first quartile = middle value between the lowest value and the median
used to determine outliers

Question 7

standard deviation

Answer 7

measurement of variability about the mean

Question 8

null hypothesis

Answer 8

hypothesis of no difference between control and experimental conditions

Question 9

How do you determine whether a finding is statistically significant?

Answer 9

compare p-value and selected significance level (usually 0.05.
p-value = calculated likelihood that results are due to random chance

Question 10

confidence interval

Answer 10

range of values around a sample mean that are used to estimate the population mean. wider interval = higher confidence level
95% is common