A proposed null hypothesis states that there is no difference between the mean weights of the population of two neighboring districts. The sample mean difference is 12 kilograms, and the standard deviation of the distribution of the difference between sample means is 9 kilograms. Which statement is true?
A.
The null hypothesis must be accepted if we choose the 68% confidence level.
B.
The null hypothesis must be accepted if we choose the 95% confidence level.
C.
The null hypothesis must be rejected if we choose the 99.7 % confidence level.
D.
The null hypothesis must be rejected if we choose the 100% confidence level.
E.
The null hypothesis must be rejected if we choose the 95% confidence level.

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

Construct the graph that models the given situation