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:
x > -18
Step-by-step explanation:
10 ( x - 9 ) > -270
Treat the inequality like an equation,
Distribute first:
10 ( x - 9 ) > - 270
10x - 90 > -270
Inverse operations:
10x - 90 > -270
       +90    +90
10x > -180
/10     /10 
x > -18
 
        
             
        
        
        
Answer:
I wouldddd but I can’t sorry 
Step-by-step explanation:
Thanks for the points though :)
 
        
                    
             
        
        
        
Answer:
x^2 -1
Step-by-step explanation:
-1×x + -1×1 + x×1 + x×x
= x^2 -x +x -1
= x^2 -1

 
        
                    
             
        
        
        
Answer:
15,625
Step-by-step explanation:
2h=120m
120/20 = 6
5^6 = 15,625