Answer:
"0.0373" seems to be the appropriate solution.
Step-by-step explanation:
The given values are:
n₁ = 43
n₂ = 35




Now,
The test statistic will be:
⇒ 
On substituting the given values in the above formula, we get
⇒ 
⇒ 
⇒ 
⇒ 
then,
P-value will be:
= 
= 
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
Option B) A and C I think
Answer: 9/20
Step-by-step explanation:
The angles are <span>supplementary
</span>
7x + x + 20 = 180
8x = 160
x = 20