Answer:
15.4
Step-by-step explanation:
-5×(-4.9) +7×(-1.3)
=24.5+(-9.1)
=24.5-9.1
==15.4
Let m be mean
Mean= sum/ n
Mean= (1720+1687+1367+1614+1460+1867+1436) / 7
m= 11151 / 7
M= 1593
Mean= 1593
Standard deviation
|x-m|^2
For 1st: |1720-1593|^2=8836
For 2nd: |1687-1593|^2=10201
For 3rd: |1367-1593|^2=51076
For 4th: |1614-1593|^2=441
For 5th: |1460-1593|^2=1689
For 6th: |1867-1593|^2=75076
For 7th: |1436-1593|^2=24649
Summation of |x-m|^2 = 171968
Standard deviation sample formula is:
S.D = sqrt((summation of |x-m|^2) / n-1)
S.D=sqrt(171968/6)
S.D=sqrt(28661.33)
S.D=169.30
Standard deviation is 169.30
The answer is 97, because when you add up 42 and 55 you get 97. Then you subtract that by 180 because a triangles angles add up to 180. 180-97=83. Z=83. Z and y are supplementary to eachother, so therefore 180-83= 97. Supplementary means they add up to 180.