Answer
$F_0=0.15$ with a P-value $\ltα$. Reject the null hypothesis.
There is enough evidence to conclude that the standard deviation of wait time at Wendy’s is more than that at McDonald’s.
Work Step by Step
$H_0:~σ_1=σ_2$ versus $H_1:~σ_1\ltσ_2$
In MINITAB, enter the McDonald’s values in C1 and the Wendy’s values in C2.
Select Stat -> Basic Statistics -> 2 Variances
Select "Each sample is in its own column"
In Sample 1 enter C1 and in Sample 2 enter C2
Click in Options. In "Ratio" select (sample variance 1)/(sample variance 2). Enter 95 in Confidence level, 1 in Hypothesized ratio. In "Alternative hypothesis" select "Difference $\lt$ hypothesized ratio". Select "Use test and confidence intervalsbased on normal distribution". Click OK.
Click OK.
$F_0=0.15$ with a P-value $\lt0.001\lt0.05=α$
