The maximum class frequency is 80. The class corresponding to this frequency is 5–7.
So, the modal class is 5–7.
l (the lower limit of modal class) = 5
f1 (frequency of the modal class) = 80
f0 (frequency of the class preceding the modal class) = 45
f2 (frequency of the class succeeding the modal class) = 55
h (class size) = 2
Mode = \(l+\left(\frac{f_1-f_0}{2f_1-f_0-f_2}\right)\times h\)
\(=5+\left(\frac{80-45}{2\times80-45-55}\right)\times2\)
\(=5+\frac{35}{60}\times2\)
\(=5+\frac{35}{30}\)
\(=6.2\)