Answer:
And rounded up we have that n=385
Step-by-step explanation:
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 95% 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)
The estimated proportion for this case is 
. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=385
Answer:
Step-by-step explanation:
Given that in a recent poll 1 of 1000 American adults, the number saying that exercise is an important part of daily life was 753.
Sample proportion = 
To find 90% confidence interval we must find std error of proportion first
As per central limit theorem, sample proportion will follow a normal distribution with mean = 0.753
Std error of proportion= 
90% Z critical value = 1.645
Margin of error = 1.645*0.01363 = 0.0224
Confidence interval lower bound = 0.753-0.0224=0.731
Upper bound = 0.775
Answer:
14x29=406 2hich would be the area
Step-by-step explanation:
Answer:
vertex = ( -6 , -3 )
focus = 
axis of symmetry = y = -3
directrix = x = 
GRAPH :
Answer:
Area of the sector = 57.26295cm²
Step-by-step explanation:
Radius of the circle=9cm
π= 3.142
Angle at B= 81° ( opposite angle of a quadrilateral)
Area of the sector = πr² * 81/360
Area of the sector = 3.142 * 9*9 * 0.225
Area of the sector= 3.142*81*0.225
Area of the sector = 57.26295cm²
