Uploaded by bernadettehenderson

Data Analysis Assignment

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Data Set 1

Question 1 – Independent sample t-test

𝐻

0

: morning class short answer score = afternoon short answer scores or 𝜇 morning = 𝜇 afternoon

𝐻

1

: morning class short answer score ≠ afternoon short answer scores or 𝜇 morning ≠ 𝜇 afternoon

X1 morning scores: 59,64,65,70,67,58,79

X2 afternoon scores: 40,45,55,55,60,70,60,63 𝑥̅ 𝑥̅ 𝑥̅

1

1

1

=

=

∑𝑥 𝑛

462

7

= 66 𝑥̅ 𝑥̅ 𝑥̅

2

2

2

=

=

∑𝑥 𝑛

448

8

= 56

68

66

64

62

60

58

56

54

52

50

Morning

Class

Afternoon

Class 𝑛

1

= 7 𝑛

2

=8 𝑥̅

1

= 66 𝑥̅

2

= 56

𝑆

2

1

= ∑

𝑆

2

1

= ∑

(𝑥−𝑥̅

1 𝑛

1

−1

)

2

(59−66

1

) 2

+(64−66

1

) 2

+(65−66

1

) 2

+(70−66

1

) 2

+(67−66

1

) 2

+(58−66

1

) 2

+(79−66

1

) 2 𝑛

1

−1

𝑆

2

1

= 50.67

𝑆

2

2

= ∑

(𝑥−𝑥̅

2 𝑛

2

−1

) 2

𝑆

2

2

= ∑

𝑆 2

2

(40−56

2

) 2

+(45−56

2

) 2

+(55−56

2

) 2

+(55−56

2

) 2

+(60−56

2

) 2

+(70−56

2

) 2

+(60−56

2

) 2

+(63−56

2

) 2 𝑛

1

−1

= 93.71

Continued…

𝑆

2 𝑝

=

(𝑛

1

− 1)𝑆

2

1

+ (𝑛

2 𝑛

1

+ 𝑛

2 −2

− 1)𝑆

2

2

𝑆

2 𝑝

=

6𝑥50.67 + 7𝑥93.71

7 + 8 − 2

𝑆 2 𝑝

=

6𝑥50.67 + 7𝑥93.71

7 + 8 − 2

𝑆

2 𝑝

=

655.97

13

𝑆 2 𝑝

= 73.85

𝑡 = 𝑥̅

1

−𝑥̅

2

√ 𝑛1

+ 𝑛2 𝑡 =

66−56

73.85

7

+

73.85

8 𝑡 = 2.2484

𝑡 ∗ (13) = 2.2160 < 2.2484

Conclusion:

Reject 𝐻

0

, scores differ between morning and afternoon classes.

Question 2 – Paired Sample t-test

𝐻

0

: short answer score = multiple choice scores or 𝜇 short answer = 𝜇 multiple choice

𝐻

1

: short answer score ≠ multiple choice scores or 𝜇 short answer ≠ 𝜇 multiple choice

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