Central tendency and variability

Question 1

is central tendency descriptive or inferential?

Answer 1

descriptive

Question 2

What are the 3 measures of central tendency?

Answer 2

mean, median, mode

Question 3

What is the difference between statistics and parameters?

Answer 3

statistics are based on a sample and parameters are based on the population.

Question 4

what to do when there are multiple or no modes?

Answer 4

find which interval (in a grouped frequency distribution) has the most number of scores.

Question 5

distribution with one mode

Answer 5

unimodal

Question 6

distribution with two modes

Answer 6

bimodal

Question 7

distribution with multiple modes

Answer 7

multimodal

Question 8

What are the 3 measures of variability?

Answer 8

range, variance, standard deviation

Question 9

how to calculate the range

Answer 9

subtract the minimum from the maximum score

Question 10

how to calculate the interquartile range (IQR)?

Answer 10

Q3-Q1=IQR
after finding the median, find the median for the lower half (Q1) and then the median for the higher half (Q3). Subtract

Question 11

Why is IQR better than range?

Answer 11

It is less susceptible to outliers

Question 12

how to calculate a deviation from the mean (variance)?

Answer 12

subtract the mean from each score, square every result, sum all the squared deviations, and divide the result by the total number of samples.

Question 13

what is sigma squared?

Answer 13

the symbol for the variance from a population, instead of a sample.

Question 14

how are variance and standard deviation connected?

Answer 14

standard deviation is the square root of the variance