descriptive and inferential statistics

Question 1

descriptive statistics

Answer 1

describe, organize and summarize data

Question 2

inferential statistics

Answer 2

making interpretations from data, using results from a sample to make conclusions

Question 3

frequency distribution

Answer 3

organize a set of scores by grouping them into a display, eligible for all scales of measurement, preliminary method of statistical analysis.

Question 4

mode

Answer 4

the score with the greatest frequency

Question 5

what is the mode, median and mean of this data set : 5, 7, 8, 8, 8,10

Answer 5

mode = 8
median = 8
mean = 7.6

Question 6

median

Answer 6

score that divides the distribution in half, useful for outliers. if there’s 2 middle scores take the average.

Question 7

mean

Answer 7

The sum of all the scores divided by the number of individual

Question 8

measures of central tendency

Answer 8

to summarize data: mean, median and mode

Question 9

measures of dispersion

Answer 9

measures the variability : standard deviation, variance and range

Question 10

measures of relationship

Answer 10

to summarize : Pearson and Spearman

Question 11

range

Answer 11

difference between the largest and smallest score, only based on 2 scores, not informative because it ignores most of the data

Question 12

measures of variance

Answer 12

better measurements of dispersion would include info from every score.

Question 13

standard deviation

Answer 13

indicates the spread of values within a sample, measures the avg distance from the mean

Question 14

standard error of the mean

Answer 14

provides a measure of how much difference is reasonable to expect between a sample and its population

Question 15

calculating variance

Answer 15

s^2= [the sum of (X-M)^2]/(n-1)

Question 16

calculating standard deviation

Answer 16

s= {square root of variance}

Question 17

calculating the standard error of the mean

Answer 17

standard deviation/ {square root of sample size}

Question 18

P value

Answer 18

probability that there is no differences between the groups, range between 0(impossible) and 1(certain). boundary is p=0.05

Question 19

null hypothesis

Answer 19

statement about the population parameter if there is no effect: assume you are wrong and conduct a study to reject the null hypothesis

Question 20

how to increase the difference between groups

Answer 20

1. increase the difference between the means
2. decrease the standard deviationbetween the means