The table below brings the time spent (in minutes) on the graded practice exam 1 and the scores of 10 randomly selected ECN 221 online students. time spent (in mins) Grade (out of 10) 12 4 57 9 10 8 35 8 5 25 17 9 22 4 37 7 6 9 Calculate the Z score when the time spent is equal to 39 minutes. Use variance = 135.73 Use four decimal places, and include the zero before the decimal place or the MINUS sign when needed. E.g., -0.1234. No credit will be given for rounding mistakes