A study was performed concerning risk factors for carotid-artery stenosis (arterial narrowing) among 264 men. The data reported for blood-glucose level (unit: mmol/L) are shown below:

	Sample size	Mean	Standard deviation
Group 1: No stenosis	156	5.3	1.4
Group 2: Stenosis	108	5.1	0.8

What is the test statistic F to check the equal variance assumption?