8)a nationwide survey of college students was conducted and found that students spend 2 hours studying. A professor at your school wnats to determine whether the time students spend at your school is...

8)a nationwide survey of college students was conducted  and found that students spend 2 hours studying. A professor at your school wnats to determine whether the time students spend at your school is significantly different  from the 2 hours . A random sample of 15 statistic students is carried out and the findings indicate an average of 1.75 hours with a standard deviation of 0.24 hours. Test at the 5% level of significance

a) the critical value of t is 1.761. the calculated value of t is -4.03

b)the critical value of t is +-2.145. the calulated value is -4.03

c)the critical value of t is +- 1.761 the calulated value is -1.041

d)the t test should not be used rather use the z test

e)the critical value of t is -4.03 the calulated value is +-2.145