Assignment:
Q1. A teacher figures that final grades in the statistics department are distributed as A-25%, B-25%, C-40%, D-5%, and F-5%. At the end of a randomly selected semester, the following number of grades were recorded. Determine if the grade distribution for the department is different than expected. Use a = 0.01.
|
Grade
|
A
|
B
|
C
|
D
|
F
|
|
Number
|
42
|
36
|
60
|
14
|
8
|
|
|
|
|
|
|
|
Q2. The contingency table below shows the results of a random sample of 200 state representatives that was conducted to see whether their opinions on a bill are related to party affiliation.
|
Party
|
Approve
|
Disapprove
|
No Opinion
|
|
Republican
|
42
|
20
|
14
|
|
Democrat
|
50
|
24
|
18
|
|
Independent
|
10
|
16
|
6
|
Q3. Find the critical value of F0 to test the claim that σ12≤σ22. Two samples are randomly selected form populations that are normal. The sample statistics are given below. Use a = 0.05.
n1= 16, s12= 8.41; n2= 15, s22= 7.84
Q4. At a college, 61 female students were randomly selected and it was found that their monthly income had a standard deviation of $133.65. For 121 male students the standard deviation was $185.57. Test the claim that the variance of monthly incomes is higher for male students that it is for female students. Use a = 0.05
Q5. Four different types of fertilizers are used on raspberry plants. The number of raspberries on each randomly selected plant is given below. Find the test statistic F to test the claim that the type of fertilizer makes no difference in the mean number of raspberries. Use α = .05
|
Fertilizer 1
|
Fertilizer 2
|
Fertilizer 3
|
Fertilizer 4
|
|
6
|
5
|
6
|
3
|
|
7
|
8
|
3
|
5
|
|
5
|
5
|
4
|
3
|
|
6
|
5
|
2
|
4
|
|
7
|
5
|
3
|
4
|
|
6
|
6
|
3
|
5
|