Answer: a) 15, b) 1.
Step-by-step explanation:
A researcher studying public opinion of proposed social security changes obtains a simple random sample of 35 adult Americans and asks them whether or not they support the proposed changes. To say that the distribution of the sample proportion of adults who respond yes, is approximately normal, how many more Americans does the researcher need to sample in the following cases?
(a) 10% of all adult Americans support the changes
Here, 
And , 
So, consider the equality, to find the value of 'n'.

So, there are
more adult Americans needed.
(b) 15% of all adult Americans supports the changes
Here, 
So, again we get that

So, there are
more adult Americans needed.
Hence, a) 15, b) 1.
If you mean 9k-7 then you have to divide if not then I don’t really get the question lol
Answer:

Step-by-step explanation:
In order to write the series using the summation notation, first we need to find the nth term of the sequence formed. The sequence generated by the series is an arithmetic sequence as shown;
4, 8, 12, 16, 20...80
The nth term of an arithmetic sequence is expressed as Tn = a +(n-1)d
a is the first term = 4
d is the common difference = 21-8 = 8-4 = 4
n is the number of terms
On substituting, Tn = 4+(n-1)4
Tn = 4+4n-4
Tn = 4n
The nth term of the series is 4n.
Since the last term is 80, L = 4n
80 = 4n
n = 80/4
n = 20
This shows that the total number of terms in the sequence is 20
According to the series given 4 + 8 + 12 + 16 + 20+ . . . + 80
, we are to take the sum of the first 20terms of the sequence. Using summation notation;
4 + 8 + 12 + 16 + 20+ . . . + 80 = 
Answer:
2x
Step-by-step explanation:
two times x is 2x
when multiplying anything
it is 1x*2
which is 2*1=2
2*x
2x
A because they add up to 190 then you subtract that from 360 and get 170