Week 4- STATS refresher

Question 1

Standard deviation is..
A) square root of variance
B) variance squared

Answer 1

A)square root of variance

Question 2

Standard error is…

Answer 2

SD / square root of sample size

Question 3

variance is..
A) scatter of data set
B) values squared
C) values square rooted

Answer 3

A) scatter of data set

Question 4

sigma squared is…

Answer 4

how spread the data is, in relation to the mean

Question 5

Population variance is..
A) variance of entire population OF INTEREST
B) variance of the sample from population
C) population variance SD
D)None of the above

Answer 5

A) variance of entire population OF INTEREST

Question 6

Sample variance is..
A)variance of population sub set
B) variance of population
C) variance of half the sample

Answer 6

A) variance of population sub set

Question 7

1st step of sample variance?
A) average values 
B) square root values 
C) square values 
D) divide values by 2

Answer 7

A) average values

Question 8

2ns step of sample variance ..
A) add value to each individual data value
B) times average by each individual data set
C) subtract average value from each individual data set
D) square average by each data set

Answer 8

C) subtract average value from each individual data set

Question 9

3rd step of sample variance..
A) calculate distance of data point from average 
B) times value by average 
C) square data points 
D) square root distances

Answer 9

A) calculate distance of data point from average

Question 10

4th set sample variance..
A) square root distances
B) square distance values 
C) add distance values 
D) divide distance values by data set

Answer 10

B) square distance values

Question 11

5th step of sample variance 
A) divide squared values by number of data points
B) add all the squares (Sum of squares) 
C) square root values then sum 
D) multiply values by 10

Answer 11

B) add all the squares (Sum of squares)

Question 12

6th step of sample variance..
A) divide sum of squares by 10
B) divide SOS by degrees of freedom (n-1)
C) X SOS by df (n-1)
D) X SOS by 10

Answer 12

B) divide SOS by degrees of freedom (n-1)

Question 13

two tailed test means you can test for an effect in both directions.. (Drug a/b performance effects) TRUE OR FALSE

Answer 13

TRUE

Question 14

one tailed is testing one direction only (DO people perform better on drug A or B) true or false

Answer 14

TRUE

Question 15

normally distributed (Gaussian distribution is a ...... curve 
A) J 
B) S 
C) Bell 
D) U

Answer 15

C) bell

Question 16

positively skewed order or mean, medium and mode.
A) Mode median mean 
B) Mean mediam mode
C) median mode mean 
D) media mean mode

Answer 16

A) mode, median, mean

Question 17

negatively skewed order or mean, medium and mode.
A) Mode median mean 
B) Mean mediam mode
C) median mode mean 
D) media mean mode

Answer 17

B) Mean mediam mode

Question 18

Mesokurtic is..
A)normal distribution
B) low distribution 
C) high curve distribution 
D) right distribution

Answer 18

A)normal distribution

Question 19

leptokurtic is a high peaked bell curve.. TRUE OR FALSE

Answer 19

TRUE

Question 20

Platykurtic has a low and flat bell curve.. true or false

Answer 20

true

Question 21

If skewness more twice the standard error skewness, you may have a..
A) normal distribution
B) small standard error
C) Skewed distribution

Answer 21

C) Skewed distribution

Question 22

If kurtosis more than twice standard error kurtosis you may have…
A) normal distribution
B) Skewed data (Right)
C) non-normal distribution

Answer 22

C) non-normal distribution

Question 23

Independent samples t test when.. 
A) 2 groups you want to compare
B) group across 2 conditions
C) pre testing only 
D) control groups comparisons only

Answer 23

A) 2 groups you want to compare

Question 24

Paired samples t test when.. 
A) 2 groups you want to compare
B) group across 2 conditions
C) pre testing only 
D) control groups comparisons only

Answer 24

B) group across 2 conditions

Question 25

Independent samples equation t=

Answer 25

(mean1-mean2)/ Square root of (SEM1squared+SEM2Squared)

Question 26

If the p value for Levene’s test in > .05 then we can assume..
A)normal data 
B) Homogeneity of variance
C) skewed data 
D) non-normal data

Answer 26

B) Homogeneity of variance

Question 27

If the p value for Levene’s test is < .05, then the assumption is..
A) correct
B) Violated
C) use bottom line of output (equal variances not assumed)
D)B,C

Answer 27

D)B,C

Question 28

Paired t-test equation..

Answer 28

mean of difference between each individual score in each test (d, with line above) / (SD/square root N)