Cho x1,x2,... Là một mẫu ngẫu nhiên có cỡ mẫu n(n>30) từ một tổng thể với E(x)u và phương sai D(x)= £^2

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?

In angle pqr find the measure of

Simplify 24÷(-2)(3)+7 a. -29 b. 3 c. 11