week 5 analysis of data

Question 1

what is variance

Answer 1

how much the data is spread from the mean

Question 2

does a spread out graph have a small or large standard deviation

Answer 2

higher sd

Question 3

does a small and tall graph have a small or large standard deviation

Answer 3

low sd

Question 4

if all values in a data set are the same, what is the standard deviation

Answer 4

0

Question 5

`what do z scores measure

Answer 5

how many standard deviations they are away from the mean

Question 6

what is included in box plot

Answer 6

1. min
2. 1st quartile
3. median
4. 3rd quartile
5. max

Question 7

if mean is greater than the median how is the data skewed

Answer 7

right skewed

Question 8

if the mean is the same as the median how is the data skewed

Answer 8

symmetrical

Question 9

if the mean is less than the median how is the data skewed

Answer 9

left skewed

Question 10

what is discriptive analysis

Answer 10

describes the sample not the population

Question 11

what are parameters

Answer 11

summary measures describing the a population

Question 12

according to the empericcal rule what percent of the data lies within 1 sd of the mean

Answer 12

68%

Question 13

according to the emperical rule what percentage of the data lies within 2 sds of the mean

Answer 13

95%

Question 14

according to the emperical rule what percentage of the data lies within 3 sds of the mean

Answer 14

99.7%

Question 15

what is chebyshevs rule

Answer 15

no matter how the data is distributed at least (1-1/k^2)x100% of the values fall within k standard deviatons of the mean

Question 16

what can scatter plots allow us to see

Answer 16

visually represent the relationship between 2 numerical values

Question 17

what does covarience measure

Answer 17

strength of relationship between two numerical values

Question 18

if cov(x,y) > 0 what direction are x and y going in relation to eachother

Answer 18

in the same direction

Question 19

if cov(x,y) < 0 what direction are x and y going in relation to eachother

Answer 19

in opposite directions

Question 20

if cov(x,y) = 0 what direction are x and y going in relation to eachother

Answer 20

are independent

Question 21

what is the coefficient of correlation

Answer 21

measures strength of relationships between two numerical values

Question 22

if the correlation coefficient is close to 1 what does that tell us about the relationship between x and y

Answer 22

strong positive relationship

Question 23

if the correlation coefficient is close to -1 what does that tell us about the relationship between x and y

Answer 23

strong negative relationship

Question 24

if the correlation coefficient is close to 0 what does that tell us about the relationship between x and y

Answer 24

weak linear relationship

Question 25

Is the mean effected by extreme outliers

Answer 25

yes

Question 26

is the median effected by extreme outliers

Answer 26

no

Question 27

can mode be used in categorical data

Answer 27

yes

Question 28

what is the geometric mean

Answer 28

rate of change in a variable over time

Question 29

what is the geometric mean rate of return

Answer 29

measures the status of an investment overtime

Question 30

what does skewness measure

Answer 30

Skewness measures the extent to which the data values are not symmetrical around the mean.