Question

A personal computer manufacturer is interested in comparing assembly times for two keyboard assembly processes. Assembly times can vary considerably from worker to worker, and the company decides to eliminate this effect by selecting a random sample of 10 workers and timing each worker on each assembly process. Half of the workers are chosen at random to use Process 1 first, and the rest use Process 2 first. For each worker and each process, the assembly time (in minutes) is recorded, as shown in Table1 Difference (Process 1 Process 2) orker Process 1 Process 2 56 51 58 53 63 74 31 82 30 53 49 26 47 16 16 26 18 58 64 50 57 10 18 75 Table 1 Based on these data, can the company conclude, at the 0.05 level of significance, that the mean assembly times for the two processes differ? Answer this question by performing a hypothesis test regarding μd (which is μ with a letter "d" subscript), the population mean difference in assembly times for the two processes. Assume that this population of differences (Process 1 minus Process 2) is normally distributed Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.)

Answer 1

H0 : mud = 0

H1: mu not equals to 0

Paired test

test statistics:
From the given data,
dbar = 13 , sd = 10.667

t = dbar /(Sd/sqrt(n))
= 13/(10.667/sqrt(10))
= 3.854

Critical value = -2.262 and 2.262

yes