A company wants to buy new accounting software for its employees. It must decide between software A and Software B. The company will decide between the two software packages based on how quickly its employees can learn how to use the software. So, seven employees are chosen to test the software packages. The number of hours that it takes each employee to learn each software package is given by:

Employee 1 2 3 4 5 6 7

x hours to learn software A 27 33 22 40 37 38 25

y hours to learn software B 30 36 25 44 37 35 23

Note that . We will define , d1= x1- y1. After doing the appropriate calculations, we find that.

d^-=-1.143 s_d = 2.80

Find the 80 % confidence interval for mean of the differences,d.