Question

Question 15 1 pts An auto company claims that the fuel efficiency of its sedan has been substantially improved. A consumer advocate organization wishes to compare the fuel efficiencies of its sedan between the 2017 and 2019 models. Each of 12 drivers drove both the 2017 and 2019 models on a highway and the fuel efficiency was measured (in miles per gallon). The same driver drove the same path for both the models. Driver Model 1 2019 31.1 324 31.3 33.5 31.7 32.0 31.8 29.9 31.0 32.8 32.7 33.8 2017 287 32.1 29.6 30.5 31.9 30.9 32.3 33.1 29.6 30.8 31.1 31.6 4. 10 11 12 Test the claim that the average fuel efficiency of the sedan has improved. What is the value of the test statistic (round off to second decimal place)? Assume normal population. Question 16 1 pts Independent random samples are selected from two normal populations. The summary statistics are given below. Assume unequal variances for the following questions m 6, -14.7, 13.4 n-9, -12.9, 2.5 Test if the mean of the first population is larger than that of the second population. Use α-005. O do not reject Ho O reject Ho

Answer 1

15)

S. No 1 2 2017 28.7 32.1 29.6 30.5 31.9 30.9 32.3 33.1 29.6 30.8 31.1 31.6 difference(d) x1-x2 2019 31.1 32.4 31.3 33.5 31.7 32 31.8 29.9 31 32.8 32.7 33.8 5.760000 0.090000 2.890000 9.000000 0.040000 1.210000 0.250000 10.240000 1.960000 4.000000 2.560000 4.840000 2d2-42.84 0.3 1.7 4. -0.2 0.5 -3.2 10 2 1.6 2.2 2d-11.8 0.983 12 total mean dbar- degree of freedom -n-1 Std deviaiton SpV(Ed-(zd)/n)/(n-1) - std error-Se So/Vn - test statistic(d-ud)/Se - 11.000 1.6851 0.4865 2.021

value of t -test statistic t =2.02

16)

null hypothesis Alternate Hypothesis 0 Hi-H2 0 2 first second 14.700 3.400 6.000 12.9000 2.5000 9.0000 S1 S2 Point estimate x1-x2 1.800 degree of freedom v min(n1,n2)-1 5.0000 for 0.05 level with right tailed test and n-1- degree of freedom, critical value of t- Decision rule 2.015 reject Ho if test statistic t>2.015 std error of difference- 1.619 (x1-X2-Ab)/se test stat t 1.11 p value : 0.158

as p value is greater than 0.05 ;

do not reject Ho