: statistics question



house
11-05-06, 03:22 AM
a) student F gets a score of 45 on a test with a mean of 78 and a standard deviation of 14. Find student F's standard score.

b) student B gets a standard score of 1.8 on a test with a mean of 35 and a standard deviation of 5. What is student B's raw score on the test?

c) if student C gets a standard score of -1.7 on a test, student D gets a standard score of 2.4 on the same test. How many standard deviation units separate these two students?


if anyone can help, I appreciate it

ewill3rd
11-05-06, 07:37 AM
My Wife has a Masters degree in Statistics.... I can print these out and put them on her desk, she's pretty busy today though.

When do you need the answers? Do you need to see the calculations?
What is this for?

dp102288
11-05-06, 12:29 PM
Damn I used to know this stuff. If I find my books, I will post what I think.

house
11-05-06, 01:02 PM
My Wife has a Masters degree in Statistics.... I can print these out and put them on her desk, she's pretty busy today though.

When do you need the answers? Do you need to see the calculations?
What is this for?

i need it for a assignment for wednesday. thanks a bunch! :thumbsup:

chuckdobbins
11-05-06, 01:59 PM
funny, how i aced my stat class just one year ago. aced it so well i was exempt from the final and still received a 4.0....and i couldnt tell ya how to solve those problems.

i think its the wording though. cuz ive helped relatives in stat, and the wording was so much different, i think its all in who writes the text.

anyways, good luck.

ewill3rd
11-05-06, 02:03 PM
She was excited at first but when she read over the questions her smile faded away.
I think she'll do it, but she was expecting it to be related to some car thing.
I'll let you know what she gets.

Murphyg
11-05-06, 04:18 PM
Statistics eh.
I do believe that statistics have proven that 47% of statistics are 76% incorrect 29% of the time.

Statistically speaking that is LOL

Sry but had to.

xxpinballxx
11-05-06, 04:59 PM
I heard 90% of the time...it works every time!

house
11-05-06, 09:05 PM
She was excited at first but when she read over the questions her smile faded away.
I think she'll do it, but she was expecting it to be related to some car thing.
I'll let you know what she gets.

thanks!

Florian
11-05-06, 09:42 PM
student F here.... I hate math.


F

railven
11-05-06, 09:49 PM
You guys remember that quote, forgot if it was Albert Einstein or Mark Twain:

"There are three kind of lies; lies, damn lies, and statistics."

[note sure if I quoted 100%]

dp102288
11-06-06, 09:08 AM
Florian is a student? I thought he was a teacher of mischief! :D

I can't find my books...damn. I am usually good with math, but I guess not stats.

TagApl4
11-06-06, 09:33 AM
a) student F gets a score of 45 on a test with a mean of 78 and a standard deviation of 14. Find student F's standard score.

b) student B gets a standard score of 1.8 on a test with a mean of 35 and a standard deviation of 5. What is student B's raw score on the test?

c) if student C gets a standard score of -1.7 on a test, student D gets a standard score of 2.4 on the same test. How many standard deviation units separate these two students?


if anyone can help, I appreciate it

Haven't taken stats since soph year college and its my first year since graduation so skills are a lil rusty, but i am a finance major none the less so I should know this.
Here are my answers PM me with questions we can talk about this to see if my methods were right, dont be mad if i got it wrong, but I'm pretty confident in my answers.

A: -2.35 mean is 78, 45 is 2.35 standard dieviations to the left making it neg
B: 42.7 35+5=40 (1 standard dieviation) + 2.7 (0.8 dieviations)= 42.7
C: 4.1 2.4--1.7=4.1

make sense to everyone else???

house
11-08-06, 10:04 PM
Haven't taken stats since soph year college and its my first year since graduation so skills are a lil rusty, but i am a finance major none the less so I should know this.
Here are my answers PM me with questions we can talk about this to see if my methods were right, dont be mad if i got it wrong, but I'm pretty confident in my answers.

A: -2.35 mean is 78, 45 is 2.35 standard dieviations to the left making it neg
B: 42.7 35+5=40 (1 standard dieviation) + 2.7 (0.8 dieviations)= 42.7
C: 4.1 2.4--1.7=4.1

make sense to everyone else???

ya thats correct
well the -2.35 is -2.53, prolly a typo on your part'

thanks!

Florian
11-08-06, 10:11 PM
huh> what?

F

Florian
11-08-06, 10:12 PM
Florian is a student? I thought he was a teacher of mischief! :D

I can't find my books...damn. I am usually good with math, but I guess not stats.

I havent been a student for 20 years...and I wasnt much of one when I was......


F

ewill3rd
11-09-06, 05:31 AM
Sorry, my wife has been too busy this week to do your homework :D

Seriously though, she's had a rough week at work.
I haven't even had a chance to talk to her this week so much has been going on.
Hope you got the answers you needed.

axnguyen
11-09-06, 08:23 AM
To answer a) and b) you just need to use the following formula:

Standard Score = (Raw Score - Mean)/Standard Deviation. Represented in variable form it looks something like:
Z = (X - u)/SD

So a) is Standard Score = (45-78)/14 = -2.357
and b) is 1.8 = (Raw Score - 35)/5, manipulate the variables to isolate the Raw Score variable and get:
Raw Score = (1.8)(5) + 35 = 44

As for c)...I'm not sure what they're asking, as for me there doesn't seem to be enough information to solve it, or maybe it's just too early in the morning :) But I'm pretty sure you need more information to solve that question. When you do find out the answers, let me know how to solve c) cause I'm curious now...

*edit* Just saw that you already agreed with the previous answers given...Hmm..Here's some info about the formula I gave: http://en.wikipedia.org/wiki/Standard_score