16 +28+32+4=80 80 total coins x.15 =12 coins sold
Answer:
The 95 percent confidence interval for the true mean metal thickness is between 0.2903 mm and 0.2907 mm
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 the margin of error 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 0.2905 - 0.0002 = 0.2903 mm
The upper end of the interval is the sample mean added to M. So it is 0.2905 + 0.0002 = 0.2907 mm
The 95 percent confidence interval for the true mean metal thickness is between 0.2903 mm and 0.2907 mm
Answer:
Step-by-step explanation: im guessing 1
Answer:

Step-by-step explanation:

Subtract x from both sides.


Square both sides.


Subtract x²-6x+9 from both sides.


Factor left side of the equation.

Set factors equal to 0.


Check if the solutions are extraneous or not.
Plug x as 2.

x = 2 works in the equation.
Plug x as 6.

x = 6 does not work in the equation.
Answer:
A.
Step-by-step explanation:
The formula for circumference is:

We know that the circumference is 8π inches. So, substitute 8π for C:

Solve for r. Divide both sides by 2π. So:

Therefore, the radius is 4 inches.
Hence, our answer is A.