Answer:
c
Step-by-step explanation:
That is the correct answer
that is correct
Answer:
(47.3, 54.1)
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
.
That is z with a pvalue of
, so Z = 1.96.
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 50.7 - 3.4 = 47.3
The upper end of the interval is the sample mean added to M. So it is 50.7 + 3.4 = 54.1
The answer is (47.3, 54.1).
The amount an investment of 16000 grows over 7 years is 16000*0.12 (i.e., 12% of 16000). So, the total amount after 7 years is 16000 + 16000*0.12, which is the same as writing 16000*1.12. Now, continue the same argument: the amount we now have 16000*1.12 grows after another 7 years to (16000*1.12)*1.12. Third 7-year period, again, (16000*1.12*1.12*)*1.12, and so on. As you can already see the number of periods shows up as the number of factors 1.12 multiplied here. A shorthand for writing that is to use the exponent, like this
.
Generalizing to n 7-year periods yields a formula:

A.43 72-12=60+3=63-20=43
20 came from temperature dropping 2 degrees every 30 minutes for 5 hours means that it dropped a total of 10 times, and 10x2=20 so the answer is 43