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) 
zscore: 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.

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