245 lines
4.0 KiB
Plaintext
245 lines
4.0 KiB
Plaintext
|
|
ans
|
|
|
|
013217
|
|
$\dfrac 16$
|
|
|
|
014083
|
|
$\dfrac{27}{100}$
|
|
|
|
014090
|
|
$\dfrac 13$
|
|
|
|
014577
|
|
$\dfrac{13}{21}$
|
|
|
|
014585
|
|
$\dfrac{6}{25}$
|
|
|
|
014591
|
|
$\dfrac{9}{10}$
|
|
|
|
014593
|
|
$\dfrac 13$
|
|
|
|
014601
|
|
$\dfrac 2{55}$
|
|
|
|
014599
|
|
$\dfrac{41}{70}$
|
|
|
|
014603
|
|
$(0,0.7)$
|
|
|
|
014598
|
|
$9$
|
|
|
|
014594
|
|
$0.14$
|
|
|
|
014094
|
|
(1) $\dfrac 15$; (2) $\dfrac 35$; (3) $\dfrac 9{10}$
|
|
|
|
014597
|
|
(1) $0.6$; (2) $X\sim \begin{pmatrix}0 & 10 & 20 & 30 \\ 0.16 & 0.44 & 0.34 & 0.06\end{pmatrix}$, $E[X]=13$
|
|
|
|
014608
|
|
$P_n=\dfrac 12(1+(-\dfrac 13)^{n-1})$
|
|
|
|
014081
|
|
$\dfrac 45$
|
|
|
|
014086
|
|
$\dfrac{9}{50}$
|
|
|
|
014091
|
|
$\dfrac{31}{120}$
|
|
|
|
014580
|
|
$\dfrac 12$
|
|
|
|
013234
|
|
$\dfrac{1}{168}$
|
|
|
|
014592
|
|
$\dfrac{95}{99}$
|
|
|
|
014602
|
|
$\dfrac 49$
|
|
|
|
014605
|
|
$0.66$
|
|
|
|
014606
|
|
$\dfrac 43$
|
|
|
|
014604
|
|
$0.1$
|
|
|
|
014607
|
|
$5$
|
|
|
|
014595
|
|
(1) $\dfrac 3{16}$; (2) $\dfrac 12$
|
|
|
|
014596
|
|
$0.03$
|
|
|
|
014600
|
|
(1) $\dfrac{12}{25}$; (2) $\dfrac 9{25}$
|
|
|
|
013220
|
|
$m>n$
|
|
|
|
014092
|
|
$63$
|
|
|
|
014629
|
|
$447$
|
|
|
|
014631
|
|
B
|
|
|
|
014632
|
|
无关
|
|
|
|
014635
|
|
\textcircled{1}\textcircled{2}\textcircled{4}
|
|
|
|
014641
|
|
$7$
|
|
|
|
014637
|
|
(1) $a=0.3$, $b=0.1$; (2) 甲离子残留百分比的平均值约为$4.05$($\%$), 乙离子残留百分比的平均值约为$6$($\%$)
|
|
|
|
014638
|
|
(1) 图略, 有明显的正相关关系; (2) $r\approx 0.97$, 相关性明显, 为正相关; (3) 拟合直线为$y=1.0173x+0.1909$, 当产品加工前含水率为$19\%$时, 加工后含水率估计为$19.5\%$
|
|
|
|
014634
|
|
(1) 图略; (2) \begin{tabular}{|c||c|c||c|c|c|}
|
|
\hline
|
|
学历 & 均值 & 中位数 & 极差 & 方差 & 标准差 \\ \hline
|
|
专科 & $14.13$ & $14.66$ & $9.94$ & $4.52$ & $2.13$ \\ \hline
|
|
本科 & $20.05$ & $19.75$ & $26.73$ & $45.84$ & $6.77$ \\ \hline
|
|
研究生 & $5.20$ & $4.54$ & $17.39$ & $14.03$ & $3.75$ \\ \hline
|
|
\end{tabular} (3) 专科与本科的相关系数约为$0.68$, 有较强的正相关性; 专科与研究生的相关系数约为$0.41$, 有较弱的正相关性; 本科与研究生的相关性约为$0.90$, 有很强的正相关性
|
|
|
|
014633
|
|
(1) 女性样本离散程度较高, 男性样本数据的第$80$百分位数为$2.7$($\%$); (2) $a=8$, 平均数约为$6.3$, 方差约为$41.3$; (3) 男性$2625$人, 女性$2375$人
|
|
|
|
013235
|
|
\textcircled{3}
|
|
|
|
013218
|
|
$50$
|
|
|
|
013237
|
|
$8$或$10$或$11$
|
|
|
|
014640
|
|
\textcircled{1}\textcircled{4}
|
|
|
|
014642
|
|
$27.6\times 10^3$
|
|
|
|
014643
|
|
$3$; $30$
|
|
|
|
014636
|
|
C
|
|
|
|
014088
|
|
B
|
|
|
|
014085
|
|
(1) $400$; (2) $4$; (3) $0.7$
|
|
|
|
014644
|
|
(1) 横截面积的平均值约为$0.06\text{m}^2$; 材积量的平均值约为$0.39\text{m}^3$; (2) $r\approx 0.97$; (3) 比例系数的估计值$\hat{k}=\dfrac{\displaystyle\sum_{i=1}^{10}x_iy_i}{\displaystyle\sum_{i=1}^{10}x_i^2}$, 约为$1210.9\text{m}^3$
|
|
|
|
014645
|
|
(1) $\chi^2=24$, 认为有关; (2) 证明略; (3) $R$的估计值为$6$
|
|
|
|
014646
|
|
(1) $X\sim \begin{pmatrix} 155 & 165 & 175 & 185 & 195 & 205 \\ 0.22 & 0.27 & 0.25 & 0.15 & 0.1 & 0.01\end{pmatrix}$, $E[X]=171.7$($\text{cm}$); (2) $0.0312$; (3) $27.25$
|
|
|
|
012942
|
|
$\begin{cases} 2, & n=1, \\ 2^{n-1} & n\ge 2\end{cases}$
|
|
|
|
012941
|
|
$\dfrac{2}{19}$
|
|
|
|
012976
|
|
$2^{\frac{n(n-1)}{2}}$
|
|
|
|
012923
|
|
$3018$
|
|
|
|
013002
|
|
$2999$
|
|
|
|
014550
|
|
$(-\infty,3)$
|
|
|
|
012966
|
|
$8$
|
|
|
|
013005
|
|
$2^{n+1}$
|
|
|
|
013935
|
|
$\dfrac{2\sqrt{3}}3$
|
|
|
|
012978
|
|
$33$
|
|
|
|
012932
|
|
$\dfrac{n}{n+1}$
|
|
|
|
012947
|
|
$\begin{cases} 2, & n=1, \\ -\dfrac{1}{3^{n-1}} & n\ge 2\end{cases}$
|
|
|
|
012971
|
|
(1) 最大项为$a_{10}-b_{10}=8976$; (2) $\{1,2,3,\cdots,13\}$
|
|
|
|
013960
|
|
(1) $a_n=2^n+1$; (2) 证明略; (3) 证明略
|
|
|
|
013000
|
|
$\dfrac 34-\dfrac{2n+3}{2(n^2+3n+2)}$
|
|
|
|
012956
|
|
$\begin{cases} 4, & n=1, \\ 2 & n\ge 2\end{cases}$
|
|
|
|
014553
|
|
$3$
|
|
|
|
012959
|
|
$\begin{cases} 1, & n=1, \\ 2^{n-2} & n\ge 2\end{cases}$
|
|
|
|
012977
|
|
$0$; $-\dfrac{63}{256}$
|
|
|
|
012982
|
|
$4$或$5$或$32$
|
|
|
|
013955
|
|
$9$
|
|
|
|
013944
|
|
$(-\infty,-2]\cup [2,+\infty)$
|
|
|
|
012936
|
|
$1830$
|
|
|
|
014560
|
|
B
|
|
|
|
013006
|
|
(1) $\{f(n)\}$是严格增数列, 证明略; (2) $(-\infty,0)\cup (0,1)$
|
|
|
|
012983
|
|
(1) $(a_1,a_2)=(0,0)$或$(1-\sqrt{2},2-\sqrt{2})$或$(1+\sqrt{2},2+\sqrt{2})$; (2) 当$n=7$时$T_n$最大, $T_7=7-\dfrac{21}{2}\lg 2$
|
|
|
|
012938
|
|
(1) $b_n=\begin{cases} 2^{\frac 32 n}, & n=2k, \\ 2^{\frac{3n-1}2} & n=2k-1\end{cases}$($k$为正整数); (2) $S_n=\begin{cases} \dfrac{10}{7}\cdot 2^{\frac 32 n}-\dfrac{10}{7}, & n=2k, \\ \dfrac{3}{7}\cdot 2^{\frac{3n-1}2}-\dfrac{10}{7} & n=2k-1\end{cases}$($k$为正整数) |