Demi is working on a presentation about a famous mathematician for her math class. She decides to make her poster in the shape o
f a plus sign.
1 answer:
The question is incomplete. The complete question is:
Demi os working on a representation about a famous mathematician for her math class. She decides to make her poster in the shape of a plus sign. What is the total area of Demi's poster? The image and the measurements of the poster are in the attachment.
Answer: Total area = 1360 square inches
Step-by-step explanation: From the attachment, the poster is formed by two rectangles one over the other and a central part, which is a square. So, the total area is the area of the 2 rectangles minus the area of the square
A = Ar - As
As these forms are regular, the area of both is A = width * length
Area of the 2 rectangle:
width = 20 in
length = 12+20+12 = 44 in
There are 2, then:
Ar = 2.20.44
Ar = 1760
Area of the square:
width = length = 20
As = 20²
As = 400
Total Area:
At = Ar - As
At = 1760 - 400
At = 1360
The total area of the poster is <em><u>1360 square inches</u></em>.
You might be interested in
Answer:
Check the explanation
Step-by-step explanation:
We want to estimate the total weight of grain on the field based on the data on a simple random sample of 5 piles out of 200. The population and sample sizes are N=200 & n=5 respectively.
1) Let Y_1,Y_2,...,Y_{200} be the weight of grain in the 200 piles and y_1,y_2,...,y_{5} be the weights of grain in the pile from the simple random sample.
We know, the sample mean is an unbiased estimator of the population mean. Therefore,
where \mu is the mean weight of grain for all the 200 piles.
Hence, the total grain weight of the population is
=
2) To calculate a bound on the error of estimates, we need to find the sample standard deviation.
The sample standard deviation is
S=
Then, the standard error of
=83.785
Hence, a 95% bound on the error of estimates is
3) Let x_1,x_2,...,x_5 denotes the total weight of the sampled piles.
Mean total weight of the sampled piles is
The sample ratio is
=0.1 , this is also the estimate of the population ratio R=
Therefore, the estimated total weight of grain in the population using ratio estimator is
lbs
4) The variance of the ratio estimator is
var(r)=
=
Hence, the standard error of the estimate of the total population is
=21.556
Hence, a 95% bound on the error of estimates is