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:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
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 ![\mu = 48, \sigma = 12](https://tex.z-dn.net/?f=%5Cmu%20%3D%2048%2C%20%5Csigma%20%3D%2012)
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
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![Z = \frac{78 - 48}{12}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7B78%20-%2048%7D%7B12%7D)
![Z = 2.5](https://tex.z-dn.net/?f=Z%20%3D%202.5)
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.
Answer:
x = 3
y = 0
Step-by-step explanation:
Answer:
The deer population decreased. The producers increased. So the number of different species increased.
Step-by-step explanation:
wolves are reintroduced ---> deer population decreases --> producer population begins to increase --> other species numbers increase as well
Answer:
the x axis goes first
Step-by-step explanation: