<u>Answer:</u>
Angle A = 39°
<u>Step-by-step explanation:</u>
We are given that there is a triangle ABC where a = 9, c = 5 and angle B = 120° and we are to find the measure of angle A.
But first we need to find the side b using the law of cosine:



Now finding angle A using law of cosine:




Therefore, the measure of angle A = 39°.
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:
C. y = -x
Step-by-step explanation:
the slope is -1 so in the formula y= mx + b
b is 0 and m is -1
so plug it in and you get y = -x