Answer:
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
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 mean subtracted by M. So it is 49.57 - 12.17 = $37.40.
The upper end of the interval is the mean added to M. So it is 49.57 + 12.17 = $61.74.
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Answer:
For 
, x = 2, or x = - 2.
Step-by-step explanation:
Here, the given expression is :
Now, using the ALGEBRAIC IDENTITY:
Comparing this with the above expression, we get
⇒Either (x-2) = 0 , or ( x + 2) = 0
So, if ( x- 2) = 0 ⇒ x = 2
and if ( x + 2) = 0 ⇒ x = -2
Hence, for , x = 2, or x = - 2.
Answer:
B, between 1 and 3 seconds.
Step-by-step explanation:
This is because the line is horizontal, and no changes were made, meaning she stopped walking.
Hope this helped.
Answer:
Third option: The graph moves left 18 units.
Step-by-step explanation:
Some transformations for a function f(x) are shown below:
If 
, the function is shifted up "k" units.
If 
, the function is shifted down "k" units.
If 
, the function is shifted left "k" units.
If 
, the function is shifted right "k" units.
In this case, we can observe that graph of 
is changed to 
Since:
We can conclude that the function is shifted left 18 units to get the function .
so I think the answer is very difficult ask to someone else
Step-by-step explanation:
xy=4
2x-y+2=0
