Tonight, please complete the following in your textbook:
Page 123-124: 7, 9, 13
Tomorrow in class we'll work with the Empirical (or 68/95/99.7) rule; then, on Thurs/Fri/Mon/Tues we'll look at finding Normal percentiles and cutoffs....that leaves us with a vocab test and a math test for next Weds./Thurs! (Then, after Columbus day...new unit!)
See you all in the a.m.! Enjoy your Tuesday!
Here are the book problems (I guess I feel like typing today...)
7.) Anna, a language major, took final exams in both French and Spanish and scored 83 on both. Her roommate Megan, also taking both courses, scored 77 (on French) and 95 (on Spanish). Overall, students on the French exam had a mean of 81 and a standard deviation of 5, and the Spanish scores had a mean of 74 and a standard deviation of 15.
a.) To qualify for language honors, a major must maintain an 85 average for all language courses taken. So far, which student qualifies?
b.) Which student's overall performance was better? (Calculate and compare 4 z-scores!)
9.) The Virginia Cooperative Extension reports that the mean weight of yearling Angus steers is 1152 pounds. Suppose weights of such animals can be described by a Normal model with a standard deviation of 84 pounds.
a.) How many standard deviations from the mean would a steer weighing 1000 lbs. be?
b.) Which steer is more unusual, a steer weighing 1000 lbs., or one weighing 1250 lbs.?
13.) Suppose the auctioneer in #11 sold a herd of cattle whose minimum weight was 980 lbs., median was 1140 lbs., Sx = 84 lbs, and IQR = 102 lbs. They sold for 40 cents a pound, and the auctioneer took a $20 commission on each animal. Then, for example, a steer weighing 1100 pounds would net the owner 0.40(1100) - 20 = $420. Find the min, median, Sx, and IQR of the net sale prices.
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