Normal distribution and standardisation

Question 1

lower SD means

Answer 1

more consistent

Question 2

if there is an error how do you report it

Answer 2

missing value

Question 3

reasons to transform data

Answer 3

scale eg units
standardise eg by sex

Question 4

what happens to the mean and SD when adding or subtracting constant numbers to each value in a data set

Answer 4

changes mean by amount added or subtracted
SD remains the same

Question 5

when multiplying or dividing to a scale …

Answer 5

mean and SD increases or decreases by the proportion its being multiplied or divided by

Question 6

Z score

Answer 6

number of SD an observation is from the mean

Question 7

positive z score =

Answer 7

observation above the mean

Question 8

negative z score =

Answer 8

observation lower than mean

Question 9

zero z score =

Answer 9

observation equals mean

Question 10

z score equation

Answer 10

observation - mean
/
SD

Question 11

mean of z scores is always

Answer 11

zero

Question 12

SD of z scores is always

Answer 12

1

Question 13

area under a normal curve =

Answer 13

1

Question 14

probability of observation being above mean =

Answer 14

0.5

Question 15

68.2% of observation lie between …

Answer 15

-1 and +1 SD

Question 16

95.4% of data falls between …

Answer 16

-2 and +2 SD

Question 17

1 z score on a normal distribution is

Answer 17

34.1% or 0.341

Question 18

normal table

Answer 18

cells show the proportion od the area under the curve that lies between the mean and a positive z score

Question 19

first column of a normal table =

Answer 19

gives z score to 1 decimal place

Question 20

how to travel a normal table

Answer 20

go down then along eg if a z score is 0.66, go down to 0.6 and then along to 0.06

Question 21

what’s does the value you find from the normal table show

Answer 21

the number of people lie between mean and the z score you used