X = 153 = 17* 9, so when <span>y = 13, x= 21*13= 273
x= 17 18 19 20 21
y= 9 10 11 12 13</span>
Okay here's an example so if we have 2, 3/2*1/2 we convert the mixed numbers to improper fractions. So in order to solve a mixed number you add the denominator, numerator and whole to get 7/2*1.2
So Multiple
7/2*1/2
Refine the fractions
7/2*2
Multiple the numbers 2*2=4 to get
7/4
and that equals 1, 3/4
·_21.21
25l546. 25 goes into 54 twice with a remainder of 4
l50↓
-----
l 46 25 goes into 46 once with 21 left
l 25
------
21
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