Question

Previous research has shown boys to be more aggressive than girls in a variety of situations. Tony T-test wonders if those sex differences hold with respect to aggressive play. He has observed a random sample of 10 boys and 10 girls playing at a local playground. He has recorded the number of aggressive behaviors per hour of play. The results are as follows (let girls be group g and boys group b):


Girls                Boys
mean_g = 20.2   mean_b = 25.6
S_g = 5                   S_b = 4
n_g = 10                  n_b = 10

Let a = 0.05

What are the null and alternative hypotheses?

(mean_b refers to mean of boys, etc.)

Question 21 options:

	1) Ho:b = 25.6, Ha:g = 20.2
	2) Ho:b-g = 0, Ha:b-g > 0
	3) Ho:b-g = 0, Ha:b-g = 0
	4) Ho:b-g = 0, Ha:b-g < 0

Question 22 (2.5 points)

Saved

What is t obtained for the previous problem?
Girls                 Boys
mean_g = 20.2    mean_b = 25.6
S_g = 5                     S_b = 4
n_g = 10                    n_b = 10

Input Boys as group1 and Girls as group 2 in your calculator.
Let a = 0.05

Question 22 options:

	1) 1.67
	2) 4.36
	3) .007
	4) 2.67

Question 23 (2.5 points)

Saved

What is the p-value for the previous problem?
Girls                Boys
mean_g = 20.2    mean_b = 25.6
S_g = 5                     S_b = 4
n_g = 10                    n_b = 10


Let a = 0.05

Question 23 options:

	1) .05
	2) 2.67
	3) .0157
	4) .007

Question 24 (2.5 points)

Saved

Which decision do you make in the previous problem?

Girls                 Boys
mean_g = 20.2    mean_g = 25.6
S_g = 5                    S_b = 4
n_g = 10                   n_b = 10


Let a = 0.05

Question 24 options:

	1) accept the null hypothesis
	2) reject the null hypothesis
	3) not enough information is given to make a decision

Answer 1