180-39-55=86°
...........................
Answer:
y = - 5x - 1
Step-by-step explanation:
The first thing to do (always) is pay attention to x =0. That at least gives you a partial answer. y = y' - 1. when you put 0 in for whatever y' is you get 0. What about the other numbers? How did they come about.
We have another clue. Whenever you put in a positive number for x, you get a negative answer for y. That's interesting. So y' has a minus sign associated with it.
y = -ax - 1 Make a>0 so there is only 1 minus sign. x cannot have an even power, because an even power would make everything positive except the -1.
So we'll start with y= - ax - 1 We'll also make the assumption that a = 1
y = - x - 1 That won't work. a >1 otherwise x = 2 won't give - 11
y = -ax - 1
let x = 2
let y = - 11 Solve for a
y = - ax - 1
- 11 = -a*-2 - 1 add 1 to both sides
-11 + 1 = - a(-2) - 1 + 1
- 10 = -2a Divide by - 2
- 10/-2 = -2a/-2
a = 5
Answer: y = - 5x - 1
Answer:
A sample of 179 is needed.
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 
.
That is z with a pvalue of 
, so Z = 1.44.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
A previous study found that for an average family the variance is 1.69 gallon?
This means that 
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
Rounding up
A sample of 179 is needed.
Answer:
C
Step-by-step explanation:
We have the expression:
Rewriting this yields:
Therefore, our answer is C.
