anonymous
  • anonymous
WILL FAN AND MEDAL The grades on the last art exam had a mean of 75%. Assume the population of grades on art exams is known to be distributed normally, with a standard deviation of 7%. Approximately what percent of students earn a score between 75% and 82%? 37.2% 84.1% 34.1% 50%
Mathematics
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
katieb
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your free account and access expert answers to this
and thousands of other questions

Hayleymeyer
  • Hayleymeyer
ohh snap, these problems! X_X
anonymous
  • anonymous
I know that i need to use the z-Score formula, But now when it says "between %75 and %82" ZSCORE = \[z= \frac{ \mu - x }{ }\]
anonymous
  • anonymous
whoops theres supposed to be a sigma under that

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

Hayleymeyer
  • Hayleymeyer
hmmm
Hayleymeyer
  • Hayleymeyer
@pooja195 help please? im not very good with this stuff! :)
Hayleymeyer
  • Hayleymeyer
Hayleymeyer
  • Hayleymeyer
yay!! help has arrived!
Luigi0210
  • Luigi0210
Don't know much stats, sorryy @imqwerty
Hayleymeyer
  • Hayleymeyer
qwerty, you better help this kid! :)
imqwerty
  • imqwerty
damn this is statistics!!!
Hayleymeyer
  • Hayleymeyer
@graysongraddylol do you still need help? :)
anonymous
  • anonymous
Yes I do @Hayleymeyer
Hayleymeyer
  • Hayleymeyer
okay, ima find you some help, cuz you seem nice
Hayleymeyer
  • Hayleymeyer
anonymous
  • anonymous
thank you :)
Hayleymeyer
  • Hayleymeyer
anytime!
Hayleymeyer
  • Hayleymeyer
anonymous
  • anonymous
anonymous
  • anonymous
phi
  • phi
mean of 75%. standard deviation of 7% score between 75% and 82%? (it is a bit confusing because our measurements are percents (on a test)... and we also have percent (under a curve) ) but we want the area under the bell curve from 75% (the mean) and 82% (which is 1 std dev to the right of the curve) how much area is between the mean and 1 std dev from the mean do you know how to figure that out ?
anonymous
  • anonymous
i have no clue what a standard deviation is :(
Hayleymeyer
  • Hayleymeyer
yay! you got help!!
phi
  • phi
do you know what a bell curve looks like?
anonymous
  • anonymous
Like this.? |dw:1440706033076:dw|
phi
  • phi
yes. and its symmetric (left side looks like right side) the exact middle is the mean
anonymous
  • anonymous
|dw:1440706112012:dw|
anonymous
  • anonymous
|dw:1440706140992:dw|
phi
  • phi
the idea is the "area under the curve" is set = to one btw, in theory the "tails" never reach the x-axis half of the area is below the mean, and 1/2 of the area is above the mean
anonymous
  • anonymous
Can't I solve this using the z-score formula.?
phi
  • phi
yes, we use z-scores. But you need to get the basic ideas so far, you know (for example) |dw:1440706289865:dw|
anonymous
  • anonymous
A friend of mine just told me it was 34.1% is that correct.?
phi
  • phi
a "standard deviation" is a way to measure how far we are away from the mean you should memorize the area from -1 std dev (below the mean) to 1 std dev (above the mean) is 68.27% of the entire area
1 Attachment
anonymous
  • anonymous
That is the emperical rule, Correct.?
phi
  • phi
in other words, you should know this |dw:1440706585153:dw|
phi
  • phi
there is a mathematical definition of the curve, and you can calculate the area. In the real world, measurements (for example, height of people), will form an almost perfect bell curve, and we can use the math to closely model the real world. back to your problem 75 is the mean 82 is 1 std dev above the mean we want this area |dw:1440706762063:dw|
phi
  • phi
you are told the area from -1 to +1 is 68.27% your know the area is symmetric about the mean (in other words, 1/2 of that 68.27 is on the left side and 1/2 is on the right side of the mean) that is enough info to figure out how much area is from 0 to 1 (it's 1/2 of the area from -1 to 1)

Looking for something else?

Not the answer you are looking for? Search for more explanations.