2 3 6 8 Espanol A personal computer manufacturer is interested in comparing the mean assembly times for two keyboard assembly processes. To do this, the company selects 15 workers at random and asks each of them to use both assembly processes. The assembly time (in minutes) for Process I is recorded for each of these the table below. workers. Then, the assembly time for Process 2 is recorded for each of the same workers. The data and the differences (Process ] minus Process 2) are shown in Worker 3 5 10 11 12 13 14 15 Process 1 84.9 605 69 0 73.4 41.5 484 35.4 73.8 83 77.5 20.6 540 32.4 Process 2 38.1 44.5 374 66 0 350 22.5 37.5 78.8 410 81:1 64.0 69 6 75.4 32.5 55.7 Difference (Process ] - Process ?) 46.8 16.0 316 74 259 53 -43.4 31.9 24 13.5 -49 5.5 215 -23.3 Send data to calculator Send data to Excel (a) Are the two samples of assembly times independent or paired (dependent) samples? Choose the best answer. independent samples X O paired (dependent) samples (b) The company wants to use the data to determine whether the assembly times of the two processes differ. The company will perform a hypothesis test of the mean of the population of differences (Process 1 minus Process 2). The sample mean and standard deviation of the sample of differences in the bottom row are 651 and 26.85, respectively. Assume that the population of these differences is approximately normally distributed. Choose the appropriate test statistic for the hypothesis test that would be performed, Then calculate that statistic, Carry your intermediate computations to three or more decimal places. Round your answer to three decimal places. (If necessary, consult a list of formulas.) Oz = 1 of = 1 It is unclear which test statistic to use