Answer:
1/12
Step-by-step explanation:
Answer:
64 feet
Step-by-step explanation:
1. perimeter would be 2x the length + 2x the width.
2. that would be 2(x+8) + 2(12)
3. simplified it would be 2x+16+24
4. combine like terms would be 2x+40
5. substitute 12 for x
6. 2(12)+40
7. 24+40
8. 64 feet
Answer:
x = 31/35
, y = 8/5
Step-by-step explanation:
Solve the following system:
{7 x - 2 y = 3
14 x + y = 14
Hint: | Choose an equation and a variable to solve for.
In the second equation, look to solve for y:
{7 x - 2 y = 3
14 x + y = 14
Hint: | Solve for y.
Subtract 14 x from both sides:
{7 x - 2 y = 3
y = 14 - 14 x
Hint: | Perform a substitution.
Substitute y = 14 - 14 x into the first equation:
{7 x - 2 (14 - 14 x) = 3
y = 14 - 14 x
Hint: | Expand the left hand side of the equation 7 x - 2 (14 - 14 x) = 3.
7 x - 2 (14 - 14 x) = (28 x - 28) + 7 x = 35 x - 28:
{35 x - 28 = 3
y = 14 - 14 x
Hint: | Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{35 x - 28 = 3
y = 14 - 14 x
Hint: | Isolate terms with x to the left hand side.
Add 28 to both sides:
{35 x = 31
y = 14 - 14 x
Hint: | Solve for x.
Divide both sides by 35:
{x = 31/35
y = 14 - 14 x
Hint: | Perform a back substitution.
Substitute x = 31/35 into the second equation:
Answer: {x = 31/35
, y = 8/5
Answer:
a. (0.6178, 5.1622)
b. (0.2637, 0.5592)
c.
Step-by-step explanation:
A.
For lead
n1 = 10
X1 = 2.89
S1 = 3.92
90% ci = 1-90%
= 0.10
TCritical = 1.833
Degree of freedom = 10-1 = 9
X1 +- TCritical * s/√n
= 2.88 +-1.833x3.92/√10
= 2.89+-2.2722
= 0.6178, 5.1622
Lead in water lies between this interval at 90% confidence level.
For cooper
n2 = 10
X2 = 0.4083
S2 = 0.2495
Alpha = 0.10
Df = 9
TCritical = 1.833
0.4083+-1.833*9.2495/√10
= 0.4084+-0.14462
= (0.26368, 0.55292)
Copper in water lies between this interval at 90% confidence level
C.
Underlying assumptions
The samples are randomly taken as well as independent. The sample size is not big enough. So it is approximately normally distributed.