A typing instructor builds a regression model to investigate what factors determine typing speed for students with two months of instruction. Her regression equation looks like: Y' = 11 + 7x1 + 5x2 + 3x3 where: Y' = typing speed in words per minute; x1= hours of instruction per week; x2= hours of practice per week; x3 = hours of typing per week necessary for school or work; A new student is taking 2 hrs of typing instruction per week, will practice 5 hrs per week and must type 2.5 hours per week for work. If the standard error of the estimate is 2, within what range do we have a 95.45% probability that that student's typing speed will be in two months? Select one:
a. 53.5 and 61.5 words per minute
b. 49.5 and 65.5 words per minute
c. 57.5 and 65.5 words per minute
d. none of the above