Using the z-distribution, we have that:
- For a 99% confidence level, a sample size of 127 is needed.
- For a 95% confidence level, a sample size of 74 is needed, meaning that a decrease in the confidence level decreases the needed sample size, as M and n are inverse proportional.
<h3>What is a z-distribution confidence interval?</h3>
The confidence interval is:
The margin of error is:
In which:
- is the sample mean.
- is the standard deviation for the population.
For a 99% confidence interval, , hence z is the value of Z that has a p-value of , so the critical value is z = 2.575.
The margin of error and population standard deviation are:
Hence we have to solve for n to find the needed sample size, as follows:
n = 126.4.
Rounding up, for a 99% confidence level, a sample size of 127 is needed.
For the 95% confidence interval, we have that z = 1.96, hence:
n = 73.3.
Rounding up, for a 95% confidence level, a sample size of 74 is needed, meaning that a decrease in the confidence level decreases the needed sample size, as M and n are inverse proportional.
More can be learned about the z-distribution at brainly.com/question/25890103
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8 and 1/2 would be probably the answer
Answer:
a1=6
a2=15
a3=24
a4=33
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Answer:
Solution given:
A(3,5)
B(8,5)
C(5,1)
D(0,1)
slope of AB=(5-5)/(8-3)=0
slope of CD=0[since it is parallel to AB]
slope of BC=(1-5)/(5-8)=-4/-3=4/3
slope of AD=4/3[since it is parallel to BC]
it is a parallelogram:
note slope=(y2-y1)/(x2-x1)
Answer:
The coefficient of correlation=0.5
Step-by-step explanation:
We are given that
Covariance between the variable x and y=18
Variance of x=16
Variance of y=81
We have to find the coefficient of correlation
We know that
Coefficient of correlation
Using the formula
Hence, the coefficient of correlation=0.5