Đối với người Việt Nam, lượng huyết sắc tố trung bình là 138,3g/l. Khám cho 80 công nhân ở nhà máy có tiếp xúc hóa chất thấy huyết sắc tố trung bình là 120g/l,
s = 15g/l. Từ kết quả trên có thể kết luận lượng huyết sắc tố trung bình của công
nhân nhà máy này thấp hơn mức chung hay không? (với mức ý nghĩa α = 0, 01)

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

To find the extreme values of a function f(x. y) on a curve x-x(t), y y(t), treat f as a function of the single variable t and use the chain rule to find where df/dt is zero. in any other single-variable case, the extreme values of f are then found among the values at the critical points (points where df/dt is zero or fails to exist), and endpoints of the parameter domain. find the absolute maximum and minimum values of the following function on the given curves. use the parametric equations x=2cos t, y 2 sin t functions: curves: i) the semicircle x4,y20 i) the quarter circle x2+y-4, x20, y20 b, g(x, y)=xy

Trent wants to buy 2 packs of trading cards for 3 dollars each. the trading card packs that trent normally buys tend to come in packs of 6, 10, 12, or 15 cards. after selecting 2 packs, trent found that the first pack of cards cost 25 cents per card, and the second pack cost 30 cents per card. trent uses this information to write the equations below in order to compare c, the number of cards in each pack.