Amateur and professional singers were the subjects of a study by Grape et al. (A-2). The researchers

investigated the possible beneficial effects of singing on well-being during a single singing lesson.

One of the variables of interest was the change in cortisol as a result of the signing lesson. Use the data

in the following table to determine if, in general, cortisol (nmol/L) increases after a singing lesson.

Let a :05. Find the p value.

Subject 2 3 5 6 7 Before 214 362 202 158 403 219 307 331 After 232 276 224 412 562 203 340 313