Question

As part of the study on ongoing fright symptoms due to exposure to horror movies at a young age, the following table was presented to describe the lasting impact these movies have had during bedtime and waking life:

		Waking symptoms
Bedtime symptoms		Yes		No
Yes		36		33
No		33		17

(a) What percent of the students have lasting waking-life symptoms? (Round your answer to two decimal places.)
%

(b) What percent of the students have both waking-life and bedtime symptoms? (Round your answer to two decimal places.)
%

(c) Test whether there is an association between waking-life and bedtime symptoms. State the null and alternative hypotheses. (Use α = 0.01.)

Null Hypothesis:

H₀: There is no relationship between waking and bedtime symptoms.

H₀: Bedtime symptoms cause waking symptoms.   

H₀: Waking symptoms cause bedtime symptoms.

H₀: There is a relationship between waking and bedtime symptoms.

Alternative Hypothesis:

H_a: Bedtime symptoms cause waking symptoms.

H_a: There is no relationship between waking and bedtime symptoms.   

H_a: There is a relationship between waking and bedtime symptoms

.H_a: Waking symptoms cause bedtime symptoms.

State the χ² statistic and the P-value. (Round your answers for χ² and the P-value to three decimal places.)

χ2	=
df	=
P	=

Conclusion:

We do not have enough evidence to conclude that there is a relationship.

We have enough evidence to conclude that there is a relationship.    

Answer 1

		Waking symptoms
		Yes	No
Bedtime symptoms	Yes	36	33	69
	No	33	17	50
		69	50	119

(a) Percent of the students have lasting waking-life symptoms

P = 69 / 119 = 0.5798 = 57.98%

(b) Percent of the students have both waking-life and bedtime symptoms

P = 36 / 119 = 0.3025 = 30.25%

(c) Test whether there is an association between waking-life and bedtime symptoms.