A nutritionist obtains the amounts of sugar (in grams) of 10 different cereals, including Cheerios, Corn Flakes, Froot Loops and seven others that the population in Puerto Rico consumes. The quantities appear below: 3, 24, 30, 47, 43, 7, 47, 13, 44, 39. Calculate the range, variance, and standard deviation of the amount of cereal sugar consumed by the population of all countries. Puerto Ricans who eat cereal. (6 points)

Exercise 3 If the standard deviation of a group of numbers is 12, what will be the value of the variance of this data? (1 point)

Exercise 4 The frequency distribution presented in the following table describes the speed at which some young people drove to get to take their classes at the university. These young people were driving on a road whose speed limit was 35 mi/h. Calculate the variance and standard deviation. (4 points) Speed frequency 42-45 22 46-49 12 50-53 6 54-57 3 58-61 1

Exercise 5 Below are the weight data (in pounds) for a group of babies born in a hospital last month: 8 6 7.5 8.5 5 7 6.5 5.5 9 Calculate the indicated percentile or quartile: (4 points) a . 85th percentile b. Quartile 1 c. 20th percentile d. Quartile 3

Exercise 6 Using the weight data for the group of babies detailed in exercise 5, prepare a box plot (summary of 5 numbers). (5 points)

Exercise 7 The mean height of men is 68 inches and its standard deviation is 2 inches. Luis is 66 inches tall. Answer: a. What difference is there between Luis's height and the average? (1 point) b. Luis's height is approximately how many standard deviations away from the mean? Use the rule of thumb to answer this question. (2 points) c. Convert Luis's height into a Z score. (2 points) d. If we consider that "common" heights are those that correspond to Z scores between -2 and 2, is Luis' height common or uncommon? (2 points)

Exercise 8 Which is relatively better: a grade of 85 in test A or a grade of 48 in test B? The scores for test A have a mean of 92 and a standard deviation of 12. The scores for test B have a mean of 55 and a standard deviation of 6. Use the measures of relative position to answer this exercise (Z Score) . (3 points)

Exercise 9 Suppose that the ages of past, present, and future presidents have a normal distribution, with a mean of 54.8 years and a standard deviation of 6.2 years. What does the rule of thumb say about the percentage of ages between 48.6 years and 61 years? (2 points)