Ron Blake, a personnel director, wants to study the accuracy level of his company's 70 secretaries. Historically, the number of word processing errors made each day by each secretary had been approximately normal with an average of eighteen, and a population standard deviation of four. Mr. Blake monitors a sample of fifteen randomly chosen secretaries today. What is the probability that the average number of errors per secretary is greater than 20

The graph of a hyperbola is shown. what are the coordinates of a vertex of the hyperbola? (0, −4) (−3, 0) (0, 0) (0, 5)

(01.03 mc) which of the following is a step in simplifying the expression x multiplied by y to the power of 2 over x to the power of negative 3 multiplied by y to the power of 3, the whole to the power of negative 4. select one: a. x to the power of negative 4 multiplied by y to the power of negative 2, the whole over x to the power of negative 7 multiplied by y to the power of negative 1. b. x to the power of negative 4 multiplied by y to the power of negative 8, the whole over x to the power of 12 multiplied by y to the power of negative 12. c. x to the power of negative 4 multiplied by y to the power of negative 8, the whole over x to the power of negative 3 multiplied by y to the power of 3. d. x to the power of negative 4 multiplied by y to the power of negative 2, the whole over x to the power of negative 3 multiplied by y to the power of 3.

Which of the following is the major negative aspect of crossover designs for research studies? a. prohibitive cost b. residual effects c-subject drepout d. incomplete randomization e. large sample size required