A particular IQ test is standardized to a Normal model, with a mean of 100 and a standard deviation of 18. a) Choose the model for these IQ scores that correctly shows what the 68-95-99.7 rule predicts about the scores. O A. В. O B. C. 68% 99 7%, 68% . H-20 95% u+ 20 H- 204 95% u+ 20 u- 204 95% Au + 20 H- 30 99,7% 0 68% + 30 99.7% + 30 + 30 H- 39 H- 30 46 64 82 100 118 136 154 46 64 82 100 118 136 154 64 82 100 118 136 154 172

Fifteen randomly selected college students were asked to state the number of hours they slept the night before. The resulting data are: 6 16 7 8 7 796 3 11 9 15 4 7 9 a) Find the mean. b) Find the median. c) Find the standard deviation. d) According to Chebysev's Theorem, at least 75% of the times will fall between what two amounts? Is the theorem accurate for this set of data? Why of Why not? e) Are any of the reported hours "unusually" high? Are any of the reported hours unusually low?

9.13 Given a sample size of 36, how large does the population standard deviation have to be in order for the standard error to be A. 1? B. 2? C. 5? D. 100?

According to a​ study, brain weights of men in country A are normally distributed with mean 1.49 kg and standard deviation 0.14 kg. Apply the empirical rule to complete each sentence. Complete parts​ (a) through​ (d). a. Complete the sentence​ "Approximately 68​% of the men have brain weights between​ _____ kg and​ _____ kg."   Approximately 68​% of the men have brain weights between nothing kg and nothing kg.