the ____ is based on only two scores in a distribution. -deviations  -variance -range -standard deviation

IQ is normally distributed with a mean of 100 and a standard deviation of 15. The middle 50% of IQs fall between what two values?  Lower ___ Upper ___

Hugo averages 76 words per minute on a typing test with a standard deviation of 12.5 words per minute. Suppose Hugo's words per minute on a typing test are normally distributed. Let X= the number of words per minute on a typing test. Then, X∼N(76,12.5).Suppose Hugo types 66 words per minute in a typing test on Wednesday. The z-score when x=66 is ________. This z-score tells you that x=66 is ________ standard deviations to the ________ (right/left) of the mean, ________.Correctly fill in the blanks in the statement above. Select the correct answer below:   A. Suppose Hugo types 66 words per minute in a typing test on Wednesday. The z-score when x=66 is 0.645. This z-score tells you that x=66 is 0.645 standard deviations to the right of the mean, 76.   B. Suppose Hugo types 66 words per minute in a typing test on Wednesday. The z-score when x=66 is −0.8. This z-score tells you that x=66 is 0.8 standard deviations to the left of the mean, 76.   C. Suppose Hugo types…

Cell Phone Lifetimes A recent study of the lifetimes of cell phones found the average is 23.8 months. The standard deviation is 5.8 months. If a company provides its 33 employees with a cell phone, find the probability that the mean lifetime of these phones will be less than 23.8 months. Assume cell phone life is a normally distributed variable, the sample is taken from a large population, and the correction factor can be ignored. Use a TI-83 Plus/TI-84 Plus calculator. Round your answer to at least four decimal places. <PX23.8)=

College students average 8.2 hours of sleep per night with a standard deviation of 45 minutes. If the amount of sleep is normally distributed, what proportion of college students sleep for more than 9 hours? Probability = %3D

z Scores LeBron James, one of the most successful basketball players of all time, has a height of 6 feet 8 inches, or 203 cm. Based on statistics from Data Set 1 “Body Data” in Appendix B, his height converts to the z score of 4.07. How many standard deviations is his height above the mean?

Consider the following sample data. Sample A: 11, 22, 33 Sample B: 81, 92, 103 Sample C: 1,100; 1,111; 1,122   (a) Find the mean and standard deviation for each sample.    Sample A: Sample B: Sample C: Mean       Sample Standard Deviation          (b) What does this exercise show about the standard deviation?  multiple choice The idea is to illustrate that the standard deviation is not a function of the value of the mean. The idea is to illustrate that the standard deviation is a function of the value of the mean.