In a study of self- medication practices, a random sample of 1,230 adults completed a ­survey. The survey reported that 441 of the persons had a cough or cold during the past month and 260 of these individuals said they had treated the cough or cold with an over- the-counter (OTC) remedy.
The data are summarized next.
Respondents reporting cough or cold………. 441
Respondents using an OTC remedy……….. 260
Respondents using specific class of OTC remedy:
Pain relievers………………………………. 110
Cold capsules……………………………….. 57
Cough remedies…………………………….. 44
Allergy remedies…………………………….. 9
Liquid cold remedies………………………. 35
Nasal sprays…………………………………. 4
Cough drops……………………………….. 13
Sore- throat lozenges………………………... 9
Room vaporizers……………………………. 4
Chest rubs…………………………………... 9
a. Provide a graphical display of the above data using percentages. Do your percentages add to 100%? Why or why not?
b. Based on the above data, for what classes of OTC remedies could you validly obtain a 95% confidence interval for the corresponding population proportion π?