Table 5.

Probability of transmission by exposure scenario and season.

Exposure Scenario	Overall		Heating season		Cooling season		P-value for paired T-test comparing heating to cooling season
	Mean (SD)	Median (Range)	Mean (SD)	Median (Range)	Mean (SD)	Median (Range)
Student to student without mask	0.091 (0.050)	0.085 (0.0031–0.29)	0.094 (0.044)	0.086 (0.021–0.22)	0.088 (0.057)	0.077 (0.0031–0.29)	0.032
Student to student with mask	0.046 (0.026)	0.042 (0.0015–0.15)	0.048 (0.023)	0.043 (0.011–0.12)	0.044 (0.030)	0.039 (0.0015–0.15)	0.033
Student to teacher without mask	0.26 (0.13)	0.25 (0.010–0.68)	0.27 (0.11)	0.26 (0.069–0.56)	0.25 (0.14)	0.23 (0.010–0.68)	0.027
Student to teacher with mask	0.14 (0.076)	0.13 (0.0051–0.42)	0.15 (0.067)	0.14 (0.034–0.33)	0.14 (0.086)	0.12 (0.0051–0.43)	0.031
Teacher to student without mask	0.35 (0.16)	0.35 (0.015–0.81)	0.37 (0.14)	0.035 (0.098–0.70)	0.33 (0.18)	0.32 (0.015–0.81)	0.025
Teacher to student with mask	0.20 (0.10)	0.19 (0.0074–0.55)	0.20 (0.089)	0.19 (0.049–0.44)	0.19 (0.11)	0.17 (0.0074–0.55)	0.029