QUESTION 16 16) Refer to the problem below to answer questions 16 & 17 A traffic engineer believes that the time needed to drive from the downtown area out to the suburbs has significantly decreased due to increased use of public transportation. A study done 5 years ago determined that it took a mean of 45 minutes with a population standard deviation of 7 minutes. Recently the mean time for 49 trips was 42 minutes. Does the data support the traffic engineer at 5%? Determine the alternative hypothesis O a. none of the choices O b. Ha: u 45 min O d. Ha: p # 45 min QUESTION 17 17) Referring to question 16 above, determine the z-score of the study result O a. +3 Ob.-3 O c.4.25 O d. none of the choices QUESTION 18 18) Referring to question 16) what would the critical z-score be for the decision rule? a.-1.65 O b.+ 1.96 O c. none of the choices O d. +1.65