Using the definition of covariance, cov(x, y) = e[(x – my)(y – my)], prove the followings. a. cov(x, y) = e(xy) - mx hy b. cov(x, y) = cov(y, x) c. cov(x, x) = var(x) d. cov(x + z, y) = cov(x, y) + cov(z, y) e. cov(ex, y)= xcov(x, y) f. var(x + y) = var(x) + var(y) + 2cov(x, y) g. var(ex) = var(x) + ej cov(x, x; )

Danielle has $127.02 in her account before making any transactions. over the course of a week, danielle makes the following transactions: transaction debit ($) credit ($) birthday check 75.00 night out 66.14 garage sale proceeds 121.58 charitable donation 42.25 doctor’s appointment 115.30 at the end of the week, how much money is in danielle’s account? a. $99.91 b. $27.11 c. $184.41 d. $142.16 select the best answer from the choices provided a b c d

Find the value of the variable and the length of each secant segment.

3.4a=57.8 what is the the value of a