Two positives make a positive
two negatives make a positive
1 negative and 1 positive make negative
1 positive and 1 negative make a negative
MCEA=90
mBEF=135
CEF is straight
AEF is right<span />
7x+(x+20)=180
Just simplify. Hope this helped:)
Answer:
And we can find this probability on this way:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problm
Let X the random variable that represent the scores on an exam of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability on this way:
The answer is 2x^2-3x-2.
Just align the polynomials and combine like terms.