Using the z-distribution, it is found that the 95% confidence interval for the difference is (-1.3, -0.7).
<h3>What are the mean and the standard error for each sample?</h3>
Considering the data given:


<h3>What is the mean and the standard error for the distribution of differences?</h3>
The mean is the subtraction of the means, hence:

The standard error is the square root of the sum of the variances of each sample, hence:

<h3>What is the confidence interval?</h3>
It is given by:

We have a 95% confidence interval, hence the critical value is of z = 1.96.
Then, the bounds of the interval are given as follows:
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Answer:
The roots are;
x = (2 + i)/5 or (2-i)/5
where the term i is the complex number representing the square root of -1
Step-by-step explanation:
Here, we want to use the completing the square method to solve the quadratic equation;
f(x) = -5x^2 + 4x -1
Set the function to zero
0 = -5x^2 + 4x - 1
So;
-5x^2 + 4x = 1
divide through by the coefficient of x which is -5
x^2 - 4/5x = -1/5
We now take half of the coefficient of x and square it
= -2/5^2 = 4/25
add it to both sides
x^2 - 4x/5 + 4/25= -1/5 + 4/25
(x- 2/5)^2 = -1/5 + 4/25
(x - 2/5)^2 = -1/25
Take the square root of both sides
x - 2/5 = √( -1/25
x - 2/5 = +i/5 or -i/5
x = 2/5 + i/5 or 2/5 - i/5
Answer:
B
Step-by-step explanation:
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