A human factors psychologist studied three computer keyboard designs. Three samp

Question

A human factors psychologist studied three computer keyboard designs. Three samples of individuals were given material to type on a particular keyboard, and the number of errors committed by each participant was recorded.

What is the correct way to write the hypotheses?

The data are as follows:

Answer Options:

Null: H0: ?1 = ?2 = ?3

Alternative: H1: ?1 = ?2 ? ?3

Null: H0: ?1 = ?2 = ?3

Alternative: H1: all three means are different from the others

Null: H0: ?1 = ?2 = ?3

Alternative: H1: ?1 ? ?2 = ?3

PART 2:

Using the same data, what are the dftotal?

2

12

14

11

PART 3

Using the same data, what is the SSwithin value?

116

46

14

70

PART 4

Using the same data, what is the critical value given an ? = .05?

4.63

3.88

3.63

D. 4.36

What is the final F-ratio?

9.14

7.20

11.28

16.50

Using the same data, what is the ?2?

.52

.38

.60

.69

What is your decision about the null hypothesis, including the verbal interpretation?

Reject H0

The type of keyboard has a significant effect on number of errors committed.

Fail to reject H0

The type of keyboard does not have a significant effect on number of errors committed.

Reject the Ho

The type of keyboard does not have a significant effect on number of errors committed.

Fail to reject H0.

The type of keyboard has a significant effect on the number of errors committed.

Keyboard A Keyboard B Keyboard C M = 1 M = 5 M =6 N = 15 T = 5 T = 25 T = 30 G = 60 SS = 12 SS = 20 SS = 14 ?X2 = 356

Explanation / Answer

1)

Null: H0: ?1 = ?2 = ?3

H1: not all means are equal

2)

dftotal =14

3)

SSwithin =46

4)

critical value given an ? = .05 =3.88

5)

final F-ratio =9.14

6)

?2 =SSbg/SST =70/116=0.60

7)

Reject H0

The type of keyboard has a significant effect on number of errors committed

c ni x?i ni*(Xi-Xgrand)2 (ni-1)*S2i keyboard A 5 1.000 45.000 12.00 keyboard B 5 5.000 5.000 20.00 keyboard C 5 6.000 20.000 14.00 grand mean= 4.000 70.000 46.00 SSTr SSE Source of variation SS df MS F P value F crit treatment 70.000 2 35.00 9.14 0.0039 3.89 error 46.000 12 3.83 total 116.000 14

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.