The anwser is 14 because 14-11=3
Answer:


As we can see the z score for Ferdinad is higher than the z score for Emilia so on this case we can conclude that Ferdinand was better compared with his group of reference.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Emilia case
Let X the random variable that represent the scores of a test, and we know that
Where
and
The z score formula is given by:
Since Emilia made 83 points we can find the z score like this:

Ferdinand case
Let X the random variable that represent the scores of a test, and we know that
Where
and
The z score formula is given by:
Since Ferdinand made 79 points we can find the z score like this:

As we can see the z score for Ferdinad is higher than the z score for Emilia so on this case we can conclude that Ferdinand was better compared with his group of reference.
Answer:
Exponential
Step-by-step explanation:
<em>Starter:</em>
According to the title:
"Every day, half a bacteria population dies."
Exponential: y = ab^x ( b > 0 , b ≠ 1)
So the answer is C.
<em>Calculations:</em>
An exponential model is of the form y = a • b^t.
If you start with population of 500 million bacteria
t = 0
so 500 million = a • b^0 = a
Since every day half the population dies then in 1 day population will be 250 million
so a = 500 million, y = 250 million and t = 1
250 million = 500 million • b^1
b = 0.5
Therefore your equation would be
y = 500 million (or whatever the pop) • 0.5^t
Where t = number of days
This could also be written in exponential form ( e = 2.73)