Question

Statistics
A set of data is normally distributed with a mean of 200 and standard deviation of 50.

What would be the standard score for a score of 100?
What percentage of scores is between 200 and 100?
What would be the percentile rank for a score of 100?

Answer 1

mean=200
standard deviation=50

Answer 2

100-200/50
-100/50
-2

Answer 3

so does that make it -2.00, right.

Answer 4

The table has:
0.4772

Answer 5

since it just asks for the standard score; it only wants the z score itself and not any table value associated with it

Answer 6

the next question asks for a percentage of scores tho

Answer 7

oh ok.
so z=-2

Answer 8

correct; what is the value of P(100<X<200) ?

and since 200 is the mean and you already found a zscore for 100 this is asking for the ztables value

Answer 9

so the number I just gave is the answer to this one? the one out of the table.

Answer 10

yep

Answer 11

the percentile id have to read up on ...

Answer 12

I know how to find a percentile from a given set of data points, just not sure how to do it from the curve

Answer 13

got it; it should be the percent of area to the left of the zscore

Answer 14

in other words P(X<100)

Answer 15

i was just going to say do we need to find both P(x=100)(P(x=200)

Answer 16

sorry to interrupt but when you get a chance could you help me out Amistre ?

Answer 17

the percentile for the mean is just 50

Answer 18

we are still on the second part right

Answer 19

when i get a chance ill see what i can do

Answer 20

this is our last one.

Answer 21

the second part was the value you got from the ztable, its a measure of the area between the mean and 100

Answer 22

which is what your ztable gives you anyways

Answer 23

ok, just making sure I was on the right page, I wasn't lol!