Discuss the below:
Q1: In one part of a test developed by a psychologist, the test subject is asked to form a word by unscrambling the letters "ciiatttsss". Given below are times (in seconds) required by 15 randomly selected persons to unscramble the letters. Construct a 95% confidence interval for standard deviation. Assume the population is approximately normal.
Times (in seconds)
68.7
27.4
26
60.5
34.6
61.1
68.6
48.4
43.6
39.5
85.3
26.3
43.4
83.7
68.9
Q2: Doing the "Statistics Modules" seems to help statistics students on their exams. Students in several statistics class are classified by grade in the course and by how many modules they completed. There wer 18 possible modules. The results are listed in the following table.
Grade in course 16 or more 9 to 15 8 or less
A 25 9 3
B 18 11 6
C 5 14 12
D or F 2 10 14
Does the data suggest that course grade and number of modules completed are dependent? Use an alpha=0.05 level of significance