Theo thống kê, ba xạ thủ A, B, C có tỷ lệ bắn trúng bia lần lượt là 70%, 75% và 60% cùng bắn vào một tấm bia (xác suất bắn trúng coi như bằng tỷ lệ bắn trúng). Gọi X là biến ngẫu nhiên chỉ số lần bắn trúng.

Bảng phân phối xác suất của X:
X 0 1 2 3
P p1 p2 p3 p4
Tìm số p2

7. problems and applications q7 congress and the president decide that the united states should reduce air pollution by reducing its use of gasoline. they impose a $0.50 tax on each gallon of gasoline sold. suppose they decided to impose the tax on consumers. in the following graph, shows the effect of a $0.50 tax on each gallon of gasoline sold imposed on consumers by shifting the demand or supply curve. demand supply 0 1 2 3 4 5 6 3.0 2.5 2.0 1.5 1.0 0.5 0 price of gasoline (dollars per gallon) quantity of gasoline (thousands of gallons) demand s 1 s 2 true or false: the price producers receive will be higher if the tax were imposed on consumers. true false if the demand for gasoline were more elastic, this tax would be effective in reducing the quantity of gasoline consumed. true or false: consumers of gasoline are by this tax. true false workers in the oil industry are by this tax.