Help for Insomniacs A recent study shows that just one session of cognitive behavioral therapy can help people with insomnia. 1 In the study, forty people who had been diagnosed with insomnia were...

A recent study shows that just one session of cognitive behavioral therapy can help people with insomnia.¹
In the study, forty people who had been diagnosed with insomnia were randomly divided into two groups of 20 each. People in one group received a one-hour cognitive behavioral therapy session while those in the other group received no treatment. Three months later, 14 of those in the therapy group reported sleep improvements while only 3 people in the other group reported improvements.


(a) Fill in the following two-way table for this data.











(b) What proportion of the 40 people in the study reported sleep improvement?


Round your answer three decimal places.


Enter your answer in accordance to item (b) of the question statement



(c) Of the people receiving the therapy session, what proportion reported sleep improvements?


Round your answer three decimal places.


Enter your answer in accordance to item (c) of the question statement



(d) What proportion of people who did not receive therapy reported sleep improvements?


Round your answer three decimal places.


Enter your answer in accordance to item (d) of the question statement



(e) If we use to denote the proportion from part (c) and use to denote the proportion from part (d), calculate the difference in proportion reporting sleep improvements, , between those getting therapy and those not getting therapy.


Round your answer three decimal places.


Enter your answer in accordance to item (d) of the question statement