12. Which of the following is not a mistake when using normal models? a. The normal model may be skewed. b. The model may have outliers when using the mean and standard deviation. c. Round all of the results to one decimal when in the middle of calculations. d. The model only applies when the distribution is unimodal and symmetric. 13. Which of the following is not true? a. Using z-scores allows us to compare values based on different units. b. Standard normal models use 0 for the mean and 1 for the standard deviation. c. Standardizing into z-scores changes the shape of the distribution of a variable. d. 99.7% of data fall within 3 standard deviations of the mean, when data is normally distributed. 14. Suppose that a Normal model described student scores in a history class. Julia has a standardized score (z-score ) of +2.5. This means that a. Julia scored 2.5 points above the class average. b. Julia's score closely resembles the average scores in her class. c. Julia scored 2.5 standard deviations above the class average. d. Julia scored 2.5 standard deviations below the class average. 15. The heights of Dutch men have a mean of 184 cm and standard deviation of 8 cm. The heights of French men have a mean of 174 cm and a standard deviation of 7.1 Which of the following back to back histograms best represent these heights? 0 cm 1.0 cm French Dutch French Dutch a 200 cm b 200 cm Dutch 0 cm French Dutch 0 cm French 200 cm 200 cm 16. Using the information in question 15. Who is taller compared to males in their country, a French man at 194 cm tall or a Dutch man at 204 cm tall? a. The Dutch man is taller because he has a higher z-score than the French man. b. The French man is taller because he has a higher z-score than the Dutch man. c. Both men when compared to other males in their country are equal in height. d. There is not enough information to answer this