Answer:
Step-by-step explanation:
3z - 7 = 14 |add 7 to both sides
3z = 21 |divide both sides by 3
z = 7
That is not correct, In a quotient or any type of equation numbers are considered rational number when they have repeating values, for this we will use {x} for example when comparing repeating values.
So if we have {a} + {b} from a equation prior to obtaining these values then we will take {a} + {b} and add {c} we will end up with {a} + {b} + {c}. We are using addition for an example.
{c} would only be a rational if it as well had repeating {x} values
{x}=Repeating value
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.
105 hope that helps and always have a great day!