Answer:
We need at least 243 stores.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error of the interval is:

For this problem, we have that:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Determine the number of stores that must be sampled in order to estimate the true proportion to within 0.04 with 95% confidence using the large-sample method.
We need at least n stores.
n is found when M = 0.04. So






Rounding up
We need at least 243 stores.
Answer:
7 hours
Step-by-step explanation:
120 x 7 = 840
Answer: 8 Hours to finish her homework.
Step-by-step explanation: We know each page, or 1 page takes 1 hour to finish. We want to know how many hours it would take to take finish 8 pages of homework. To find this, simply multiply 1 by 8. (1 hour per page, or 1 hour for each of the 8 pages.)
1 x 8 = 8.
So it will take Meredith 8 hours to finish her homework.
Answer:
10.5 feet
Step-by-step explanation:
In this problem, we have two similar triangles:
- One consists of the mailbox, its shadow and the hypothenuse
- The other one consists of the tree, its shadow and the hypothenuse
The two triangles are similar, so they have same proportions between their sides: therefore, we can apply the rule of three:

where
m = 36 in is the height of the mailbox
is the shadow of the mailbox
t is the height of the tree
is the length of the shadow of the tree
Solving for t, we find the height of the tree:

And since
1 feet = 12 inches
The height of the tree in feet is

I got 0.7071067812
Hope this helps