Aneuroscientist measures the reaction times (in seconds) during an experimental session in a sample of cocaine-addicted (n = 8), morphine-addicted (n = 12), and heroin-addicted rats (n = 6). mean reaction times in each sample were 11, 18, and 13 seconds, respectively. what is the weighted mean for all three samples? hint: the overall mean is not 14.0 seconds. (round your answer to two decimal places.)

Describe the symmetry of the figure. identify lines of symmetry, if any. find the angle and the order of any rotational symmetry.

Students are given 3 minutes to complete each multiple-choice question on a test and 8 minutes for each free-responsequestion. there are 15 questions on the test and the students have been given 55 minutes to complete itwhich value could replace x in the table? 5507-m23-m8(15-m)8(15)-m

Assume that females have pulse rates that are normally distributed with a mean of mu equals 72.0 beats per minute and a standard deviation of sigma equals 12.5 beats per minute. complete parts (a) through (c) below. a. if 1 adult female is randomly selected, find the probability that her pulse rate is between 65 beats per minute and 79 beats per minute. the probability is? b. if 16 adult females are randomly selected, find the probability that they have pulse rates with a mean between 65 beats per minute and 79 beats per minute. the probability is? c. why can the normal distribution be used in part (b), even though the sample size does not exceed 30?