在σ未知且n较大时,估计μ95%可信区间的公式是[img=2x2]17da560369e01c4.png[/img]
未知类型：{'options': ['17da5701b1855a6.png±1.96S', '17da5701b1855a6.png±2.58S[img=2x2]17da560369e01c4.png[/img][img=2x2]17da560369e01c4.png[/img][img=2x2]17da560369e01c4.png[/img]', '17da5701b1855a6.png±2.58[img=20x25]17da41fd47ea756.png[/img]', '17da5701b1855a6.png±1.96[img=20x25]17da41fd47ea756.png[/img]', '17da5701b1855a6.png±[img=39x24]17da5a74b6cbe47.png[/img]'], 'type': 102}
未知类型：{'options': ['17da5701b1855a6.png±1.96S', '17da5701b1855a6.png±2.58S[img=2x2]17da560369e01c4.png[/img][img=2x2]17da560369e01c4.png[/img][img=2x2]17da560369e01c4.png[/img]', '17da5701b1855a6.png±2.58[img=20x25]17da41fd47ea756.png[/img]', '17da5701b1855a6.png±1.96[img=20x25]17da41fd47ea756.png[/img]', '17da5701b1855a6.png±[img=39x24]17da5a74b6cbe47.png[/img]'], 'type': 102}
举一反三
- 在σ未知且n较大时,估计μ95%可信区间的公式是 未知类型：{'options': ['17da5701b1855a6.png±1.96S', ' [img=13x23]17da5701b1855a6.png[/img]±2.58S', ' [img=13x23]17da5701b1855a6.png[/img]±2.58[img=20x25]17da41fd47ea756.png[/img]', ' [img=13x23]17da5701b1855a6.png[/img]±1.96[img=20x25]17da41fd47ea756.png[/img]', ' [img=13x23]17da5701b1855a6.png[/img]±[img=39x24]17da5a74b6cbe47.png[/img]'], 'type': 102}
- 求不定积分[img=132x48]17da6537fc8dad6.png[/img]； （ ） A: -(4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) B: (4*(sin(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) C: (4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) D: (4*(cos(x/2)/2 + 2*cos(x/2)))/(17*exp(2*x))
- 求微分方程[img=143x21]17da5f14490e50e.png[/img]的通解,实验命令为(). A: dsolve(D2y-2*Dy+5*y=sin(2*x),x)ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x) B: dsolve('D2y-2*Dy+5*y=sin(2*x)','x')ans =cos(2*x)*(sin(4*x)/17 - cos(4*x)/68 + 1/4) - sin(2*x)*(cos(4*x)/17 + sin(4*x)/68) + C1*cos(2*x)*exp(x) - C2*sin(2*x)*exp(x) C: dsolve(D2y-2*Dy+5*y=sin(2*x),'x','y')ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x)
- 正常情况下,老年人每日适宜的饮水量(除去饮食中的水)为( )。[img=2x2]17da560369e01c4.png[/img] 未知类型：{'options': ['1000ml[img=2x2]17da560369e01c4.png[/img]', ' 1500ml[img=2x2]17da560369e01c4.png[/img]', ' 2000ml[img=2x2]17da560369e01c4.png[/img]', ' 2500ml[img=2x2]17da560369e01c4.png[/img]', ' 3000ml'], 'type': 102}
- 老年人的营养需求中,脂肪供给能量应占总热量的( )。[img=2x2]17da560369e01c4.png[/img] 未知类型：{'options': ['10%~20%[img=2x2]17da560369e01c4.png[/img]', ' 20%~30%[img=2x2]17da560369e01c4.png[/img]', ' 40%~50%[img=2x2]17da560369e01c4.png[/img]', ' 50%~60%', ' 55%~65%'], 'type': 102}