Exam #1

Question 1

Summation of x divided by n

Answer 1

mean

Question 2

Summation of (x- pop. mean) squared
Summation of (x- sample mean) squared

Answer 2

Sum of squares (ss)

Question 3

SS divided by N

ss divided by N-1

Answer 3

variance

Question 4

square root of variance squared

Answer 4

standard deviation

Question 5

X - pop mean divided by variance

X - sample mean divided by variance

Answer 5

z score of individuals

Question 6

sample mean - population mean divided by (variance divided by square root of sample size)

Answer 6

z-score of means

Question 7

Nominal

Answer 7

categorical

Question 8

ordinal

Answer 8

rank order

Question 9

interval

Answer 9

equal distance between measurements

Question 10

rational

Answer 10

meaningful zero

Question 11

Kurtosis

Answer 11

peakedness of the distribution

Question 12

lepokurtosis

Answer 12

a lot of scores in the middle

Question 13

platykurtosis

Answer 13

flat

Question 14

When do you use the median?

Answer 14

1. skewed/non normal
2. undetermined values (SAT scores)
3. open ended items (1,2,3, >4)
4. ordinal

Question 15

When do you use a bar graph?

Answer 15

Nominal (qualitative) (categorical)

Question 16

when do you use a histogram?

Answer 16

interval or ratio (quantitative)

Question 17

What effects variability?

Answer 17

1. outliers
2. sample size if really small
3. stability under sampling
4. open ended distributions

Question 18

SS interpret

Answer 18

Summed squared distance from the mean

Question 19

variance interpret

Answer 19

typical squared distance from the mean

Question 20

Standard deviation interpret

Answer 20

typical distance between an individual score and an average score

Question 21

sampling error

Answer 21

error between a sample statistic and the corresponding population parameter

Question 22

distribution of sample means

Answer 22

set of means from all the possible random samples of a specific size selected from a specific population

Question 23

expected value of M

Answer 23

the mean of the distribution of sample means, equal to the population mean

Question 24

standard error of M

Answer 24

standard deviation of sample mean

variance(m) = variance/ square root of n

Question 25

Central Limit Theorem

Answer 25

normal is n=30 or more

Question 26

what is standard error determined by?

Answer 26

(1) the size of the sample and

(2) the standard deviation of the population from which the sample is selected

Question 27

Law of large numbers

Answer 27

states that the larger the sample size (n), the more probable it is that the sample mean is close to the population mean

Question 28

Use of a sample not randomly selected in an experiment

Answer 28

limits the degree to which the results can be generalized to a population

Question 29

We generally like the standard deviation when we are trying to describe a sample of data because

Answer 29

it is expressed in units of the raw metric

Question 30

SS definition

Answer 30

the sum of the squared deviation

Question 31

variance definition

Answer 31

the mean squared deviation

Question 32

Standard deviation definition

Answer 32

square root of the variance and provides a measure of the standard distance from the mean

Question 33

mean definition

Answer 33

the sum of the scores divided by the number of scores