There were 21 students in travis's fourth-grade class at the end of the school year. during the year four new students joined his class, and two moved away. one student was transferred to another fourth-grade teacher. how many students were in travis's class at the beginning of the school year?

(b) suppose that consolidated power decides to use a level of significance of α = .05, and suppose a random sample of 100 temperature readings is obtained. if the sample mean of the 100 temperature readings is x⎯⎯ = 60.990, test h0 versus ha and determine whether the power plant should be shut down and the cooling system repaired. perform the hypothesis test by using a critical value and a p-value. assume σ = 5. (round your z to 2 decimal places and p-value to 4 decimal places.)