82% 2% 34% 16%
Do you have a TI calculator?
No, if I did I would be able to do many more questions.
ok we'll use a table then
first convert the raw score x = 95 to a z-score use the formula z = (x-mu)/sigma
in this case, mu = 80 and sigma = 15
What is the "raw score"?
x = 95 is the raw score
it's the score on the test the z-score is the transformed score to the standard normal distribution
z = (x-mu)/sigma z = (95-80)/15 z = ???
yes z = 1
ie, z = 1.00
Now use a table like this one https://www.stat.tamu.edu/~lzhou/stat302/standardnormaltable.pdf locate the row that starts with `1.0` and find the column that has `.00` at the top the intersection of this row and column has the number ______ (fill in the blank)
I don't understand what this number actually is.
this number represents the probability of getting a z-score less than 1.00 in notation form, we say `P(Z < 1.00) = 0.84134` so there's approx a 84.134 % of getting a z-score less than 1.00 in other words, there is a 84.134 % chance of getting a test score less than 95
subtract 0.84134 from 1 to get the probability of getting a score larger than z = 1 or x = 95
compute 1 - 0.84134
Wait so how do you get the probability from there?
1 - 0.84134 = 0.15866
0.15866 = 15.866% which rounds to 16%
we have some normal curve |dw:1440808310147:dw|
Yeah. :) Thank you so much!
I'm glad that everything is making sense now
Me too, I usually pick things up very quickly, but I just couldn't hack this question. :)