mean u	383
	stdev σ	46
	x1	350
	x2	400
1	z	-0.72	-0.7174
2	p(x ≥ 383)	0.5	50.00%
3	p(x ≤ 350)	0.24	23.66%
4	p(x ≥ 400)	0.36	35.59%
5	p(350 ≤ x ≤ 400)	0.41	40.76%
6	p(x ≤ ____ ) = 0.20	344.29
7	p(x ≥ ____ ) = 0.20	421.71