0 Question 1 B 0/1 pt '0 3 Z 99 6) Details The Empirical Rule tells us that for the Normal distribution, . about % of all values fall within 1 standard deviation of the mean, . about % of all values fall within 2 standard deviations of the mean, and - about % of all values fall within 3 standard deviations of the mean. Shade the standard normal curve (normal distribution of z-scores) to represent the area that covers the middle 95% of all values. You can click the drop-down menu to switch the shading to be between two values, then click and drag the arrows to set the boundaries for your answer. Shade: . Click and drag the arrows to adjust the values. Question 2 60/1 pt 0 3 # 99 0 Details The maintenance department at the main campus of a large state university receives daily requests to replace fluorecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 59 and a standard deviation of 9. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 59 and 86? Do not enter the percent symbol. ans = Question Help: [ Video 1 [) Video 2 Submit Question Question 3 6 0/1 pt D 3 # 99 0 Details The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 61 and a standard deviation of 8. Using the Empirical Rule rule, what is the approximate percentage of lightbulb replacement requests numbering between 53 and 61? Do not enter the percent symbol. ans Question Help: Video Submit Question Question 4 0/1 pt 0 3 # 99 0 Details The Acme Company manufactures widgets. The distribution of widget weights is bell-shaped. The widget weights have a mean of 48 ounces and a standard deviation of 9 ounces. Use the Empirical Rule. Suggestion: sketch the distribution in order to answer these questions. a) 68% of the widget weights lie between and b) What percentage of the widget weights lie between 21 and 57 ounces? c) What percentage of the widget weights lie below 66 ? Question Help: Video Submit Question Question 5 0/1 pt 0 3 # 99 0 Details In a mid-size company, the distribution of the number of phone calls answered each day by each of the 12 receptionists is bell-shaped and has a mean of 40 and a standard deviation of 11. Using the empirical rule, what is the approximate percentage of daily phone calls numbering between 7 and 73? Do not enter the percent symbol. ans - Submit Question Question 6 6 0/1 pt 0 3 # 99 0 Details The time to complete an exam is approximately Normal with a mean of 38 minutes and a standard deviation of 8 minutes. The bell curve below represents the distribution for testing times. The scale on the horizontal axis is equal to the standard deviation. Fill in the indicated boxes. " = 38 D = 8 - 30 p-20 H+20 p+ 30 Question Help: [ Video Submit QuestionQuestion 7 0/1 pt 0 3 # 99 0 Details The graph illustrates a normal distribution for the prices paid for a particular model of HD television. The mean price paid is $1400 and the standard deviation is $70. 1190 1260 1330 1400 1470 1540 1610 Distribution of Prices Q What is the approximate percentage of buyers who paid more than $1540? What is the approximate percentage of buyers who paid between $1330 and $1470? What is the approximate percentage of buyers who paid between $1400 and $1610? What is the approximate percentage of buyers who paid between $1330 and $1400? What is the approximate percentage of buyers who paid more than $1610? What is the approximate percentage of buyers who paid between $1400 and $1540? Question Help: Video 1 ) Video 2 Submit Question Question & 0/1 pt 0 3 # 99 0 Details The results of a common standardized test used in psychology research is designed so that the population mean is 165 and the standard deviation is 40. A subject earns a score of 173. What is the z-score for this raw score? z-score- Question Help: Video Submit Question Being comfortable converting between z-scores and actual values is important when working with the empirical rule. Of course we can always use the formula z = to do our conversions. However, if we are given a z-score, and wish to convert it to an actual value, we can also just use the definition of a z- score to do this. Recall: A z-score is the number of standard deviations away from the mean. Example: If the mean of all the class scores on a math test was 72 with a standard deviation of 4, find the scores of a person who had ... ...a z-score of 2: Since the person has a z-score of 2, then the student scored 2 standard deviations above the mean. So, we can just start at the mean of 72, and go up by the standard deviation of 4, two times. I = 72 + 2(4) = 80 Thus, a student who scored 2 standard deviations above the mean had an actual score of 80 points on the exam. ..a z-score of -1: This student scored 1 standard deviation below the mean, so we can start at the mean of 72, then go down by 1 standard deviation of 4. I = 72 - 1(4) = 68 Thus, a student who scored 1 standard deviation below the mean had a actual score of 68 points on the exam. Question 9 0/1 pt 3 # 99 0 Details Adult men have heights with a mean of 69.0 inches and a standard deviation of 2.8 inches. Find the height of a man with a z-score of 1 (to 2 decimal places) Submit