In: Statistics and Probability
The weights (in pounds) of 6 vehicles and the variability of their braking distances (in feet) when stopping on a dry surface are shown in the table. Can you conclude that there is a significant linear correlation between vehicle weight and variability in braking distance on a dry surface? Use alpha = 0.01
Weight, x 5940 5390 6500 5100 5820 4800
Variability in braking distance, 1.74 1.92 1.93 1.61 1.69 1.50
y
Setup the hypothesis for the test
H0: p ___ 0
Ha: P___ 0
Identify the critical value(s). Round to three decimal places as needed.
Calculate the test statistic.
Weight X | Breaking Distance Y | X * Y | |||
5940 | 1.74 | 10335.6 | 35283600 | 3.0276 | |
5390 | 1.92 | 10348.8 | 29052100 | 3.6864 | |
6500 | 1.93 | 12545 | 42250000 | 3.7249 | |
5100 | 1.61 | 8211 | 26010000 | 2.5921 | |
5820 | 1.69 | 9835.8 | 33872400 | 2.8561 | |
4800 | 1.5 | 7200 | 23040000 | 2.25 | |
Total | 33550 | 10.39 | 58476.2 | 1.9E+08 | 18.1371 |
To Test :-
H0 :-
H1 :-
Test Statistic :-
t = 2.075
Test Criteria :-
Reject null hypothesis if
Critical value
-4.6041 < 2.075 < 4.6041
Result :- We fail to Reject null hypothesis
Decision based on P value
P - value = P ( t > 2.075 ) = 0.1066
Reject null hypothesis if P value <
level of significance
P - value = 0.1066 > 0.01 ,hence we fail to reject null
hypothesis
Conclusion :- We Accept H0
There is no linear correlation between variables.