The following group of values was entered into the TVM solver of a graphing calculator. N = 108; I% = 6.6; PV = ; PMT = -620 FV = 0; P/Y = 12; C/Y = 12; PMT:END. Which of these expressions will return the same value for PV? (I mostly need help with the explaining part)

(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.)