The amount of a particular impurity in a batch of a certain chemical product is a random variable with mean value 4.0 g and a standard deviation 1.2 g. If 40 batches are independently prepared, what is the (approximate) probability that the sample average amount of impurity X is between 3.5 and 3.8 g

What is the domain and range of each function 1. x (3, 5, 7, 8, 11) y ( 6, 7, 7, 9, 14) 2. x (-3, -1, 2, 5, 7) y (9, 5, 4, -5, -7)

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.