Answer:
The ratio is 2:3. 10m:15m is the fraction 10/15. Reduce to 2/3. The ratio is 2:3.
Step-by-step explanation:
70-40= 30
30/2 = 15
40/2= 20
15 x 20 = 300
Answer:b
Step-by-step explanation:
Work backwards.
Start with z = 4.
Now deal with the middle equation
y + 3z = 11 Substitute z = 4 and solve for y
y + 3(4) = 11 Subtract 12 from both sides
y + 12 = 11
y + 12 - 12 = 11 -12 Combine terms on the left and right
y = - 1 Now use the top equation for x
z = 4 z still = 4
2x + 4(-1) +3(4) = 14
2x - 4 + 12 = 14 Solve 3z
2x + 8 = 14 Subtract 8
2x + 8 - 8 = 14 - 8 Combine
2x = 6 Divide by 2
x = 6/2
x = 3
Answer
x = 3
y = - 1
z = 4
Answer:
The lower bound of the interval is 88.9mm and the upper bound is 93.1mm.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 91 - 2.1 = 88.9mm.
The upper end of the interval is the sample mean added to M. So it is 91 + 2.1 = 93.1 mm
The lower bound of the interval is 88.9mm and the upper bound is 93.1mm.
