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Table below shows number of students who failed different math courses in Spring

ID: 3226414 • Letter: T

Question

Table below shows number of students who failed different math courses
in Spring (Expected Frequency) and in Fall (Observed Frequency) semesters:

Course

Spring
Expected (E)
Frequency

Fall
Observed (O)
Frequency

(E – O)2

(E – O)2/E

College Algebra

12

15

Statistics

18

14

Calculus-I

10

11

Calculus-II

8

6


Null Hypothesis Ho: distribution of failed students is the same in Spring and Fall semesters.
Use Chi-Square test with the significance level 0.10 to check if given data support or do not
support Ho (should we reject or do not reject Ho).

a) Calculate Chi Square (sum of the last column).
b) Use Excel function =CHIDIST(Chi-Square, df) to find p-value for this case.

c) Compare p-value with the significance level 0.10.
If p-value is less than 0.10 then reject Ho.
If p-value is greater than 0.10 then do not reject (accept) Ho.

Show work

Course

Spring
Expected (E)
Frequency

Fall
Observed (O)
Frequency

(E – O)2

(E – O)2/E

College Algebra

12

15

Statistics

18

14

Calculus-I

10

11

Calculus-II

8

6

Explanation / Answer

a)

X2 = 2.238889

b) P-value = 0.01

c) Reject the nul hypothesis as p-value < 0.1

Course E O (O-E)2 (O-E)2 / E Algebra 12 15 9 0.75 Stats 18 14 16 0.88889 Calculas I 10 11 1 0.1 Calculas II 8 6 4 0.5 2.238889