PACE STATS 001 Name: Examination #2 Tue Wed Thurs ID#:

 1. (20 points)

 Speedy Root Canal w/o anesthesia Two semesters of statistics Total Day Students 45 60 105 Pace 30 38 68 Total 75 98 173

 2. (15 points)

 z-score:  -0.625⇒0.2357and 8.13 ⇒0.5000

 3. (15 points)

 4. (25 points)

 A. LABLE VARABLES IN BOXES BELOW N=225 S=4 Marging of error = 0.7840 Point est. of μ =15 Part 1: Point est. of μ =15 Part 2: 0.7840 (Margin of error) Part 3: The 95% CI: 14.216  to 15.784 B. A more precise estimate can be obtained by (1) collecting more data so as to increase the sample size or (2) by lowering the confidence level to something like 90% – the confidence interveal will be narrower

 5. (25 points)

 A. LABLE VARABLES IN BOXES BELOW N=15 S=3 Marging of error = 2.3060 Point est. of μ =20 Part 1: Point est. of μ =20 Part 2: 2.3060(Margin of error) Part 3: The 99% CI= 17.694 to 22.306

 Extra Credit (25 points)

 Ex. #1 (Parts A & B must be complete to receive credit)

 A. (10 points) LABLE VARABLES IN BOXES BELOW N=64 S=5 Marging of error = 1.6099 Point est. of μ =20 Part 1: Point est. of μ =20 Part 2: 1.6099(Margin of error) Part 3: The 99% CI= 18.3901 to 21.6099 B.  (5 points) African Gray Parrots are quite intelligent, (M = 20, SD = 5, 99% CI [18.39, 21.61])

 Ex. #2 (Parts A & B must be complete to receive credit)

 A. (5 points) Research Question: Do adolescents spend more time interacting with online friends than with real friends? B. (5 points) The independent variable is Friends, which has two levels, online and real friends The depedent variable is the amount of time adolescents interact with online and real friends.