Table II.

Best-fit curve data for the control group (B)

Class	Class interval	Centre of class interval xk0	Deviation from the centre xk = xk0 – xśr	Standardised result z = xk/s	Y value	Number
						Expected f S	Obtained f 0	Decision
1	[36-41]	38.5	−39.38	−2.70	0.0104	0.11	1
2	[42-47]	44.5	−33.38	−2.29	0.0290	0.30	1
3	[48-53]	50.5	−27.38	−1.88	0.0681	0.70	0
4	[54-59]	56.5	−21.38	−1.47	0.1354	1.39	0
5	[60-65]	62.5	−15.38	−1.06	0.2274	2.34	3	χ2 = 16.205 > 15.9870.10; 10
6	[66-71]	68.5	−9.38	−0.64	0.3250	3.35	1	H 0 rejected
7	[72-77]	74.5	−3.38	−0.23	0.3885	4.00	3
8	[78-83]	80.5	2.62	0.18	0.3925	4.04	5
9	[84-89]	86.5	8.62	0.59	0.3352	3.45	6
10	[90-95]	92.5	14.62	1.00	0.2419	2.49	4
11	[96-101]	98.5	20.62	1.42	0.1455	1.50	1