Discussion:
Determine whether the samples are independent or dependent
1. The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patient who use a placebo drug.
2. The effectiveness of a new headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient.
3. The effect of caffeine as an ingredient is tested with a sample of regular soda and another sample with decaffeinated soda.
4. The accuracy of verbal responses is tested in an experiment in which individuals report their heights and then are measured. The data consist of the reported height and measure height for each individual.
Find the number of successes x suggested by the given statement
1. Among 660 adults selected randomly from among the residents of one town, 30.2% said that they favor stronger gun-control laws.
2. Among 1400 randomly selected car drivers in one city, 8.29% said that they had been involved in an accident during the past year.