28.6 / 89.4 = 0.75 / x
cross multiply
28.6x = 67.05
x = 67.05 / 28.6
x = 2.34 <==
Answer:
C. 0.98
Step-by-step explanation:
Let x be the mean of Company A and B annual profit and x/2 and y are standard deviation of Company A and B annual profit.
P(B<0) = 0.9*P(A<0)
P(Z<(0-x)/y) = 0.9*P(Z<(0-x)/(x/2))
P(Z<-x/y) = 0.9*P(Z<-2)
P(Z<-x/y) = 0.0205
x/y =2.04
Or y/x = 1 /2.05
y/x =0.49
Ratio of the standard deviation of company B annual profit to the standard deviation of company A annual profit =y/(x/2)
= 2*(y/x)
= 2*0.49
= 0.98
Answer:
No
Step-by-step explanation:
=2•2•2=8
=3•3=9
8≠9
Step-by-step explanation:
let number be x
3(4+x)=2x
12 + 3x = 2x
12 = 2x - 3x
12 = -x
x= -12
Answer:
Part A:
x + y = 80
x + 20 = y
Part B:
Pam spends 30 minutes practicing math every day.
Part C:
It is not possible for Pam to have spent 60 minutes practicing dance because this means she must have practiced math for 40 minutes (60 - 20 = 40). This would total out to 100 minutes of total practice, not 80 minutes. Therefore, this is impossible.
Step-by-step explanation:
Part A:
"She spends 80 minutes every day practicing dance and math."
x + y = 80
"She dances for 20 minutes longer than she works on math."
x + 20 = y
Part B:
Solve for x:
x + 20 = y
Isolate variable x:
x = y - 20
Plug in this new value for the first equation:
y - 20 + y = 80
Combine like terms:
2y - 20 = 80
Isolate variable y:
2y = 100
y = 50
Plug in the new value of y into any equation:
x + 50 = 80
Isolate variable x:
x = 30
Part C:
x + 20 = y
x + 20 = 60
x = 40
x + y = 80
40 + 60 = 80
100 = 80
Impossible.