2020-수학-가형-홀수-18

문제

2020-수학-가형-홀수-18

풀이

from sympy import *
from sympy import stats
m, x = symbols('m x')
mean = symbols("m", positive = True) 
std = 2
# Using sympy.stats.Normal() method 
X = stats.Normal("x", mean, std) 
pdf = stats.density(X)(x) 

#pprint(pdf)
pdf
\[\displaystyle \frac{\sqrt{2} e^{- \frac{\left(- m + x\right)^{2}}{8}}}{4 \sqrt{\pi}}\]
solveset(-(12-10)**2 <= -(20-m)**2, m, S.Reals)
\[\displaystyle \left[18, 22\right]\]
val = 0
for mean in range(18,23):
    Y = stats.Normal('Y', mean, 2)
    b = stats.P(Y<=24).evalf()
    a = stats.P(Y<=21).evalf()
    print([mean,b-a])
    if b-a>val:
        val = b-a
val
[18, 0.0654573032372280]
[19, 0.152445588605681]
[20, 0.285787406777808]
[21, 0.433192798731142]
[22, 0.532807207342556]
\[\displaystyle 0.532807207342556\]