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:
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:
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:
More can be learned about the z-distribution at brainly.com/question/25890103
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