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:
Option D. 
Step-by-step explanation:
Let
x------>the greatest possible value
we know that
If four people write the number zero, then the average will be

Answer:
100 i think
Step-by-step explanation:
Answer:
31
Step-by-step explanation:
210 ft ÷ 7 ft = 30
There are 30 7-ft lengths of fence.
Think of putting a post at the end of each 7-ft length. That means you need 30 posts. Now you must add 1 post for the beginning.
Answer: 31
2.) Given: There are 30 students. 24 are wearing sneakers.
Work: We can figure this out by finding the exact percentage of sneaker-wearers in the class.
To find the percentage, you do 24/30. 24/30 is equal to 80%.
Answer: Joe is wrong. The percentage of students wearing sneakers is 80% and not 70%.
3.) Given: There are 40 people total. 2 women per 3 men.
Work: 2:3 women to men
If we multiply both by 10, we will get 50 people in total.
20:30 = 50
So we need to shrivel this down to 40 by taking out 5 on both sides of the ratio.
50 - 5 - 5 = 15:25 = 40
But the ratio need to be divisible by 2 because of the 2 women that are needed per 3 men. We can do this by moving over one human to the men’s side.
There are 14 women and 26 men. I didn’t use any of the strategies there listed because I don’t even remember what those are. I’m in grade 9. I would say that the ratio table works best because I just used ratios...
4.) Given: Find simplified fraction of silicon. 100%.
Work: Add all things up to find out the denominator for the fraction. They will equal 100.
So the fraction is 28/100.
We can divide this fraction by 4.
7/25
This is the simplified form.
Answer: 7/25