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Two randomly selected groups of 200 students each were taught two different memorization methods over a four week period. At the end of four weeks a memorization test with a maximum possible score of 100 was given. The confidence interval of the difference in the two group population mean scores on the memorization test was (0.8 to 1.4). What statement best reflects the results of this study?

A company has 300 employees. Each year, there is a 30% turnover rate for the employees. The total number of employees who leave each year follows a binomial distribution. Now, we want to use the normal approximation to this binomial distribution. Then in this normal distribution, the mean is ______ and the standard deviation is _____.

A poll of 120 adults who shopped at Walmart found that 54 have purchased a flat screen television Based on these data, what is the margin of error for a 95% confidence interval of the proportion of adults who have purchased a flat screen television.

Suppose X and Y are continuous random variables with joint pdf f(x, y) = 24xy if 0 < x, 0 < y, and x + y < 1, and zero otherwise. (a) Find E(XY). (b) Find the covariance of X and Y. (c) Find the correlation coefficient of X and Y. (d) Find Cov(3X, 5Y). (e) Find Cov(X + 1, Y – 2). (f) Find Cov(X + 1, 5Y – 2). (g) Find Cov(3X + 5, X).

For a Gaussian discriminant classifier, where you model P(y = 1) (using a binomial) and P(x|y = 0) and P(x|y = 1). The latter have distinct means µ0 and µ1, and a shared covariance matrix Σ . If we classify an example for which we know inputs x1, . . . xn−1, but the value of xn is missing.  The value of xn is filled by its class-conditional means, E(xn|y = 0) and E(xn|y = 1). Using the log-odds ratio, can someone provide a mathematical justification