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ormed to measure the effect of nutrition on attention span. Three 5 students wer

ID: 3356420 • Letter: O

Question

ormed to measure the effect of nutrition on attention span. Three 5 students were randomly assigned to one of 3 meal plans, and then the umber of minutes they paid attention in a morning class was measured. No LightFull Meal Plan Breakfast Breakfast Breakfast 14 16 12 17 10 12 16 15 12 13 6.0 8 7 Sample Data 13 10 9.4 5.3 14 Sample mean Sample variance 6.5 Source of Variation Between Groups Within Groups Total df 2 12 14 MS 29.27 5.93 4.94 58.5 71.2 129.7 Find the 95% Fisher's LSD intervals for the test. Indicate which samples are significantly different, if any.

Explanation / Answer

Answer:

MINITAB used

Method

Null hypothesis

All means are equal

Alternative hypothesis

Not all means are equal

Significance level

= 0.05

Equal variances were assumed for the analysis.

Analysis of Variance

Source

DF

Adj SS

Adj MS

F-Value

P-Value

Factor

2

58.53

29.267

4.93

0.027

Error

12

71.20

5.933

Total

14

129.73

Calculated F=4.93, P=0.027 which is < 0.05 level. Ho is rejected. We conclude that there is significant difference between the three meal plans.

Means

Factor

N

Mean

StDev

95% CI

No

5

9.40

2.30

(7.03, 11.77)

Light

5

14.00

2.55

(11.63, 16.37)

Full

5

13.00

2.45

(10.63, 15.37)

Pooled StDev = 2.43584

Fisher Individual Tests for Differences of Means

Difference
of Levels

Difference
of Means

SE of
Difference

95% CI

T-Value

Adjusted
P-Value

Light - No

4.60

1.54

(1.24, 7.96)

2.99

0.011

Full - No

3.60

1.54

(0.24, 6.96)

2.34

0.038

Full - Light

-1.00

1.54

(-4.36, 2.36)

-0.65

0.528

Simultaneous confidence level = 88.44%

Fisher test shows that No breakfast is significant with light and full breakfast.

Light and full breakfast are not significant.

Null hypothesis

All means are equal

Alternative hypothesis

Not all means are equal

Significance level

= 0.05