Answer:
> a<-rnorm(20,50,6)
> a
[1] 51.72213 53.09989 59.89221 32.44023 47.59386 33.59892 47.26718 55.61510 47.95505 48.19296 54.46905
[12] 45.78072 57.30045 57.91624 50.83297 52.61790 62.07713 53.75661 49.34651 53.01501
Then we can find the mean and the standard deviation with the following formulas:
> mean(a)
[1] 50.72451
> sqrt(var(a))
[1] 7.470221
Step-by-step explanation:
For this case first we need to create the sample of size 20 for the following distribution:

And we can use the following code: rnorm(20,50,6) and we got this output:
> a<-rnorm(20,50,6)
> a
[1] 51.72213 53.09989 59.89221 32.44023 47.59386 33.59892 47.26718 55.61510 47.95505 48.19296 54.46905
[12] 45.78072 57.30045 57.91624 50.83297 52.61790 62.07713 53.75661 49.34651 53.01501
Then we can find the mean and the standard deviation with the following formulas:
> mean(a)
[1] 50.72451
> sqrt(var(a))
[1] 7.470221
Answer:
option-B
Step-by-step explanation:
we are given system of inequality as


now, we can check solution
At (0,0):
we can plug x=0 and y=0
and check inequality


so, this is FALSE
now, we can check second inequality


So, this is TRUE
so, option-B
Answer:
B . . . . . .. . ....... .......
Answer:
C
Step-by-step explanation:
Perimeter of a triangle is the sum of all the sides.
A triangle has 3 sides, so if we add up all the 3 sides lengths <em>(given as expressions here)</em> of the triangle, we will have the perimeter.
Perimeter = 
<em>Now combining like terms we have:</em>
<em>
</em>
Answer choice C is the correct one.
Answer:
B. P′ (−4, 0)
Step-by-step explanation:
You can look at the graph. The X-axis always goes first. SO -4 is first because it's on the x-axis. ANSWER= (-4, 0)