Answer:B
Step-by-step explanation:
B is has a proportional x and y value because they're increasing at the same rate which is 0
A^2 +a-6. You use the method of foiling where you multiply the first two terms, the the outside terms, the inside terms, then the last terms. You would do a•a, then a•-2 the a•3 then 3•-2. You would get a^2 -2a +3a -6. Then combine like terms to get your answer.
This comes from subtracting 4 from both sides.
Answer:
x = 15
Step-by-step explanation:
3x / 3 = 45 / 3 x = 15
Answer:
A customer who sends 78 messages per day would be at 99.38th percentile.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Average of 48 texts per day with a standard deviation of 12.
This means that 
a. A customer who sends 78 messages per day would correspond to what percentile?
The percentile is the p-value of Z when X = 78. So



has a p-value of 0.9938.
0.9938*100% = 99.38%.
A customer who sends 78 messages per day would be at 99.38th percentile.