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
The second one on the top right
Answer:
t = 4 x 12
Step-by-step explanation:
t = total # of marbles
Equation: t = 4 x 12
=48
The inequality would be
0.75q ≥ 0.70(q+1)
q is defined as the number of questions he answers after the first one. We are told he gets 75% of those correct; 75%=75/100=0.75. This gives us 0.75q.
Since he gains proficiency on the exercises, the total number he gets correct has to be at least 70%. This means the inequality would have the symbol greater than or equal to, as it cannot be less and have him gain proficiency.
He has already answered 1 question and answers q more; this gives us a total of q+1. Since he gains proficiency, the cutoff was 70%; 70%=70/100=0.70. This gives us the expression 0.70(q+1).
Our total inequality would then be 0.75q ≥ 0.70(q+1)
It will take you 3/4 of an hour, or 45 minutes to paint 1 wall.