Answer:
positive 3
Step-by-step explanation:
-8 + 11 is 3. the other way you can think of it is by subtracting 8 from 11.
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
26*5 is 130
He'll have ten left over if each student in year 11 has one :) Hope this helps!
Answer:
C (37, 77)
Step-by-step explanation:
<h3>Option A:</h3>

Option A is not a solution.
<h3>Option B:</h3>

Option B is not a solution.
<h3>Option C:</h3>

Option C is a solution.
Hope this helps.
A)If the order of the speakers is important, we have 20x19x18x17, or 116,280 different options.
b) If order is not important, then we have 20 choose 4, or 4845 different slates. ☺☺☺☺