Answer:
a) 6.68th percentile
b) 617.5 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:

a) A student who scored 400 on the Math SAT was at the ______ th percentile of the score distribution.



has a pvalue of 0.0668
So this student is in the 6.68th percentile.
b) To be at the 75th percentile of the distribution, a student needed a score of about ______ points on the Math SAT.
He needs a score of X when Z has a pvalue of 0.75. So X when Z = 0.675.




Answer:
y = 2x - 3
Step-by-step explanation:
y - - 3 = 2(x-0)
y + 3 = 2x
y = 2x -3
Answer:
CD = two square root of 10 end square root
Step-by-step explanation:
To find the length of a segment, use the distance formula. Substitute the order pairs for the endpoints of the segment. CD has the end points (-7, -4) and (-1, -2).

Answer:
d
Step-by-step explanation:
Answer:
-2
Step-by-step explanation:
Since the roots are known and the function is a quadratic function, we can write down the function:
y = (x+3)(x-2/3) since when the roots are plugged in, the function gives 0.
Standard form means that the function has to be expanded:
y = (x+3)(x-2/3) = 
y = 
The constant term is -2.