Your band is one of 8 bands competing at the battle of the bands. The order of the performances is determined at random. The fir
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Answer:
1) n=48
2) n=298
3) n=426
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the real population proportion of interest
represent the estimated proportion for the sample
n is the sample size required (variable of interest)
represent the critical value for the margin of error
The population proportion have the following distribution
Part 1
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 can assume that the estimated proportion is 0.23 for the 25 to 30 group. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=48
Part 2
The margin of error on this case changes to 0.04 so if we use the same formula but changing the value for ME we got:
And rounded up we have that n=298
Part 3
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)
We can assume that the estimated proportion is 0.23 for the 25 to 30 group. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=426
Answer: First option.
Step-by-step explanation:
<h3> The missing picture is attached.</h3><h3></h3>You can use these methods to solve a System of Equations and find the value of the variables:
A. Substitution method.
B. Elimination method.
In this case, given the following System of equations:
The most efficient method to solve it is the Substitution Method. The procedure is:
Step 1: Solve for one of the variables from the most convenient equation.
Step 2: Make the substitution into the other equation and solve for the other variable in order to find its value.
Step 3: Substitute the value obtained into the equation from Step 1 and evaluate, in order to find the value of the other variable.
Based on this, you can identify that first step to solve the given System of equations, is solving for "x" from the second equation:
Answer:
It is proved that exixts at (0,0) but not differentiable there.
Step-by-step explanation:
Given function is,
- To show exixtance of
we take,
exists.
And,
exists.
- To show f(x,y) is not differentiable at the origin cheaking continuity at origin be such that,
where m is a variable.
which depends on various values of m, therefore limit does not exists. So f(x,y) is not continuous at (0,0). Hence it is not differentiable at (0,0).