Nice, already in vertex form
y=a(x-h)^2+k
(h,k) is vertex
therfor since (-3,6) is vertex
we are looking for something like
y=a(x-(-3))^2+6 simplified to
y=a(x+3)^2+6
A is ansre
I think the answer is 17.5 years
Answer:
99.89% of students scored below 95 points.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What percent of students scored below 95 points?
This is the pvalue of Z when X = 95. So



has a pvalue of 0.9989.
99.89% of students scored below 95 points.
Lets look at the hours they are open from. 9 am - 4:30 pm which is 7 and a half hours a day. Now we multiply 7 1/2 by the number of days they are open, which will be 7 1/2 * 255 = 1,912.5. This means that the library is open 1,912 1/2 hours a year.
I hope I've helped! :)