I strongly disagree bc it was an corporation for the public in 1995
Answer:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:
Step-by-step explanation:
A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the probability that the sample mean is in the interval 47<=X<53. Is the assumption of normality important. Why?
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
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where
and 
Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:

We can find the probability required like this:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:

We’re given two numbers - 1.46 and 0.751 - and since we know that they were both collected last week (although from two separate barrels), we want to add these two numbers up. Aligning the numbers up ( for example, the 1 in 1.46 should align with the 0 in 0.751 because they’re both in the ones place, or the place before the decimal), we get
1.46
+0.751
————
-.—1
To fill in the blanks, we want to start by adding the 6 and 5, which is 11. Since the first digit of 11 is 1, we can carry the 1 into the space to the left to get
1
1.46
+ 0.751
————-
-.-11
For the next digit, we have 4+7=11, but we add the one on the top to get 12. 12-10=2, so we have
1
1.46
+ 0.751
————-
-.211
Since 1+1+0=2, we have 2.211 as our answer.
Feel free to ask further questions!
The function is

1. let's factorize the expression

:

the zeros of f(x) are the values of x which make f(x) = 0.
from the factorized form of the function, we see that the roots are:
-3, multiplicity 1
3, multiplicity 1
0, multiplicity 3
(the multiplicity of the roots is the power of each factor of f(x) )
2.
The end behavior of f(x), whose term of largest degree is

, is the same as the end behavior of

, which has a well known graph. Check the picture attached.
(similarly the end behavior of an even degree polynomial, could be compared to the end behavior of

)
so, like the graph of

, the graph of

:
"As x goes to negative infinity, f(x) goes to negative infinity, and as x goes to positive infinity, f(x) goes to positive infinity. "