Answer:
c
Step-by-step explanation:
just took the test
A. 2.8x+3
B. -73/156
C. 6 10/21+ 10 6/7
D is already simplified
Answer:


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.
Middle 85%.
Values of X when Z has a pvalue of 0.5 - 0.85/2 = 0.075 to 0.5 + 0.85/2 = 0.925
Above the interval (8,14)
This means that when Z has a pvalue of 0.075, X = 8. So when
. So




Also, when X = 14, Z has a pvalue of 0.925, so when 




Replacing in the first equation





Standard deviation:




It’s Seven Hundred Thirteen point forty-nine
Answer:
B
Step-by-step explanation:
4x-5y=2 ...(1)
10x-21y=10 ...(2)
(1)+2(2) gives
24x-47y=22