Answer:
A sample of 499 is needed.
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 is given by:
In this question, we have that:
90% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 90% confidence level with an error of at most 0.03
We need a sample of n, which is found when 
. So
Rounding up
A sample of 499 is needed.
Answer:
A
Step-by-step explanation:
10x3=30
15x2=30+10=40
15x3=45 movies for less
You need to do the following equation:
(5/12)*(3/10)
5*3=15
12*10=120
15/120=5/40 of the adults who visited were men.
Answer:
Step-by-step explanation:
Given that the figure is made up of portion of a square and a semicircle, we have;
BC ≅ AB = 6 cm
The area of semicircle BC with radius BC/2 = 3 is 1/2×π×r² = 1/2×π×3² = 4.5·π cm²
Triangle ABC = 1/2 × Area of square from which ABC is cut
The area of triangle ABC = 1/2×Base ×Height = 1/2×AB×BC = 1/2×6×6 = 18 cm²
The area of the figure = The area of semicircle BC + The area of triangle ABC
The area of the figure = 4.5·π cm² + 18 cm² = 
.
