Answer:
The 80% confidence interval for the mean per capita income in thousands of dollars is between $21.3 and $21.9.
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 21.6 - 0.3 = $21.3.
The upper end of the interval is the sample mean added to M. So it is 21.6 + 0.3 = $21.9.
The 80% confidence interval for the mean per capita income in thousands of dollars is between $21.3 and $21.9.
A properly written number in scientific notation has the form:
+/- A*10^n
where +/- is either plus or minus
A is a decimal number (or integer) where 1<= A < 10
and n is a positive or negative integer.
According to these rules,
120,000,000 is written in scientific notation as
1.2 * 10^8
so we need to move the decimal point 8 places to the left and multiply by 10^8.
9/10 is greater than 6/10
6/10 <9/10
Answer:
:D
Step-by-step explanation:
19.35 = 7062.75 mm²