A study conducted by Columbia University compared the cognitive ability of stroke patients three months after they'd been admitted to the hospital with a control group of those who had not had a stroke. The bar graph below is based on the study, and illustrates the number of errors made on a neuropsychological test by the patients who had had a stroke with those who had not had a stroke. Cognitive Impairment After Stroke 70 60 50 40 Frequency 30 20 Number of Errors Made Control Group OStroke Patients The information and graph in this problem is based on the report found at http /www.ncbinim.nih.gov/pmc/articles/PMC1072451/pdf/jnnpsyco0032-0074.pdf Use the bar graph to answer the following. a. How many stroke patients made no errors on the test? people b. How many total members of the control group made 1, 2, or 3 errors on the test? people c. How many fewer people from the control group made 6 errors on the test when compared to the group of stroke patients? people