Question

Question 7 options:

Researchers watched groups of dolphins off the coast of Ireland in 1998 to determine what activities the dolphins partake in at certain times of the day ("Activities of dolphin," 2013). The numbers in table below represent the number of groups of dolphins that were partaking in an activity at certain times of days:

Table: Dolphin Activity

Activity	Period				Row Total
	Morning	Noon	Afternoon	Evening
Travel	6	6	14	13	39
Feed	28	4	0	56	88
Social	38	5	9	10	62
Column Total	72	15	23	79	189

Is there enough evidence to show that the activity and the time period are independent for dolphins? Test at the 1% level.

(v) Using calculator, spreadsheet, or online calculator, determine test statistic:

Enter value in decimal form rounded to nearest thousandth.

(vi) Using tables, calculator, or spreadsheet: Determine and enter p-value corresponding to test statistic.

Enter value in decimal form rounded to nearest ten-thousandth

(vii) Comparing p-value and ? value, which is the correct decision to make for this hypothesis test?  

A. Reject H_o

B. Fail to reject H_o

C. Accept H_o

D. Accept H_A

(viii) Select the statement that most correctly interprets the result of this test:

A. The result is not statistically significant at .01 level of significance. Sufficient evidence exists to support the claim that the activity and the time period are NOT independent for dolphins.

B. The result is not statistically significant at .01 level of significance. There is not enough evidence to support the claim that the activity and the time period are NOT independent for dolphins.

C. The result is statistically significant at .01 level of significance. There is not enough evidence to support the claim that the activity and the time period are NOT independent for dolphins.

D. The result is statistically significant at .01 level of significance. Sufficient evidence exists to support the claim that the activity and the time period are NOT independent for dolphins.

Answer 1

The statistical software output for this problem is:

Contingency table results:
Rows: var10
Columns: None

	Morning	Noon	Afternoon	Evening	Total
Travel	6	6	14	13	39
Feed	28	4	0	56	88
Social	38	5	9	10	62
Total	72	15	23	79	189

Chi-Square test:

Statistic	DF	Value	P-value
Chi-square	6	68.464567	<0.0001

Warning: over 20% of cells have an expected count less than 5.
Chi-Square suspect.

Hence,

v) Test statistic = 68.465

vi) p - Value = 0.0000

vii) Option A is correct.

viii) Option D is correct.