Answer:
And rounded up we have that n=421
Step-by-step explanation:
We know that the sample proportion have the following distribution:
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by 
and 
. And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that 
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
We assume that a prior estimation for p would be 
since we don't have any other info provided. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=421
The first picture would be choice answer c because the number of x's represent how many birds wings are this size. The number on the tic mark represents the size of the wing span. So you would take the number of x's times the tic mark represented under it. There are 3 birds with 3 1/8 wingspan so it wold be 3 1/8 *3. Hoped this helps for the first one!
Answer:
B. 
Step-by-step explanation:
Total number of students surveyed = 420
Of which only 
prefer rap.
So, the number of people who like rap is the product of the fraction of people who prefer rap and the total number of students.
The number of students that prefer rap is 105
So the equation is .
You need 1.6 Grams. Hope this helped :P
The answer is 2.8. or around there
