Answer:
a) 
D. 9.74
b) 
B. 74
Step-by-step explanation:
Part a
We have the following dataset given:
69 74 75 62 70 93 64 69 61 88 67 77 87 90 66 91 77 63 82 82 71 74 76 65 83
We can begin calculating the sample mean with the following formula:
And replacing we got:
Now we can calculate the sample deviation with the following formula:
And after replace we got:
Part b
For this case we need to sort the value on increasing way:
[1] 61 62 63 64 65 66 67 69 69 70 71 74 74 75 76 77 77 82 82 83 87 88 90 91 93
And the median would be the value in the position 13 and we got:
8/3 cups or 2 2/3
2/3 × 4/1 = 8/3
if u divide 3 into 8 it gives u 2 times with 2 places left
the 2 places equal 2/3
2 whole OR 6/3 + 2/3 = 8/3 OR 2 and 2/3
There are 10 seniors in the class, from which 4 should be chosen by the teacher. The order of the chosen students does not matter. This means that we speak of combinations. THe equation for calculating the number of possible combinations is:
C=N!/R!(N-R), where N is the total number of objects and R is the number of objects we select from the N
In our case, N=10, R=4.
C= 10!/4!*6!=10*9*8*7*6!/6!*4*3*2*1=<span>10*9*8*7/24=5040/24=210
There are 210 different ways for the teacher to choose 4 seniors in no particular order.</span>
