46 12 0 56 35

40 20 10 0 14

13 20 16 40 11

Based on these data, which of the following statements is true?

a. The critical value for the test conducted at a 0.05 level of significance is t = -1.7613

b. The belief about the mean being less than 26 minutes is not supported by the sample data.

c. The test statistic is calculated to be approximately t = -0.863

d. All of the above are true.