A dose of the drug captopril, designed to lower systolic blood pressure, is administered to 10

randomly selected volunteers. The blood pressure for each of the subjects was recorded before the dose was administered and after the dose was taken. The results are in the table below.

Before pill: 120 136 160 98 115 110 180 190 138 128

After pill: 118 122 143 105 98 98 180 175 105 112

Is there evidence to indicate that the drug captopril is effective in lowering systolic blood pressure? Justify your answer statistically (include conditions, a histogram, steps using a t-test, and accurate conclusions).