1% of 19,500= 195
6% = 1%x6 = 195x6 = 1170
19500+1170=20670
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:
61.57 ft
Step-by-step explanation:
Look at the picture. You need to find the base value.
so we can sue the cosine formula here.
cos x° = adjacent / hypotaneous
cos 52 ° = adj / 100
adjacent = 100 cos 52°
=61.57 ft