设<img class=jc-formula data-tex=X\sim N(\mu ,{ \sigma }^{ 2 }) src=https://huaweicloudobs.ahjxjy.cn/D44F0120779583142A69C24868B5C1F6.png style=vertical-align: middle;/>,则下列关于<img class=jc-formula data-tex=P(|X-\mu |\le k\sigma ) src=https://huaweicloudobs.ahjxjy.cn/67EE95446536DB9CFCF8AE44C1E8B8C7.png style=vertical-align: middle;/>的表述正确的是

【单选题】【消耗次数：1】

① 仅与<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=vertical-align: middle;/>有关

② 仅与σ有关

③ 仅与k有关

④ 与<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=white-space: normal; vertical-align: middle;/>，k均无关

参考答案：

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相关题目

【单选题】无论<img class=jc-formula data-tex={ \sigma }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/BA735BCEABA38585A1A566FA21ECF803.png style=vertical-align: middle;/>是否已知，正态总体均值<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=vertical-align: middle;/>的置信区间的中心都是

① <img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=white-space: normal; vertical-align: middle;/>

② <img class=jc-formula data-tex={ \sigma }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/BA735BCEABA38585A1A566FA21ECF803.png style=white-space: normal; vertical-align: middle;/>

③ <img class=jc-formula data-tex=\bar { X } src=https://huaweicloudobs.ahjxjy.cn/D42F5A34C15652BB7248EBC94AFB2C95.png style=vertical-align: middle;/>

④ <img class=jc-formula data-tex={ S }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/5C807F9269FA1DA14B9E68BA5641C607.png style=vertical-align: middle;/>

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【单选题】设总体X服从N(μ,σ2)，<img class=jc-formula data-tex={ \sigma }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/F82DC67D9EBCC9F258673A10C47B1E61.png style=vertical-align: middle;/>已知，总体均值<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=vertical-align: middle;/>的置信区间长度L与置信度<img class=jc-formula data-tex=1-\alpha src=https://huaweicloudobs.ahjxjy.cn/D162262640DEF85B0D80C1ECE04D2598.png style=vertical-align: middle;/>的关系是

① 当<img class=jc-formula data-tex=1-\alpha src=https://huaweicloudobs.ahjxjy.cn/D162262640DEF85B0D80C1ECE04D2598.png style=font-family: Arial, sans-serif; font-size: 14px; white-space: normal; vertical-align: middle;/>缩小时，L缩短

② 当<img class=jc-formula data-tex=1-\alpha src=https://huaweicloudobs.ahjxjy.cn/D162262640DEF85B0D80C1ECE04D2598.png style=white-space: normal; font-family: Arial, sans-serif; font-size: 14px; vertical-align: middle;/>缩小时，L增大

③ 当<img class=jc-formula data-tex=1-\alpha src=https://huaweicloudobs.ahjxjy.cn/D162262640DEF85B0D80C1ECE04D2598.png style=white-space: normal; font-family: Arial, sans-serif; font-size: 14px; vertical-align: middle;/>缩小时，L不变

④ 以上说法均错误

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【单选题】设<img class=jc-formula data-tex={ X }_{ 1 },\cdots ,{ X }_{ n } src=https://huaweicloudobs.ahjxjy.cn/8159F7186DE77C735294288BB1F8C1F1.png style=vertical-align: middle;/>是来自总体<img class=jc-formula data-tex=X src=https://huaweicloudobs.ahjxjy.cn/18E2773B1E2835B209E7E51B85285E80.png style=vertical-align: middle;/>的样本，且<img class=jc-formula data-tex=EX=\mu src=https://huaweicloudobs.ahjxjy.cn/39618736AA44811087C44938D156DBC3.png style=vertical-align: middle;/>，则下列是<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/44B6A27E434C1345C3CEEB7A5249665D.png style=vertical-align: middle;/>的无偏估计的是

① <img class=jc-formula data-tex=\frac { 1 }{ n } \sum _{ i=1 }^{ n-1 }{ { X }_{ i } } src=https://huaweicloudobs.ahjxjy.cn/C47B85208815D85D3DD90DFEC473F7FF.png style=vertical-align: middle;/>

② <img class=jc-formula data-tex=\frac { 1 }{ n-1 } \sum _{ i=1 }^{ n }{ { X }_{ i } } src=https://huaweicloudobs.ahjxjy.cn/F592094A4BE03E45216F0FE940311E37.png style=vertical-align: middle;/>

③ <img class=jc-formula data-tex=\frac { 1 }{ n } \sum _{ i=2 }^{ n }{ { X }_{ i } } src=https://huaweicloudobs.ahjxjy.cn/72F0F6F417A0E32959CC0BA9BC395311.png style=vertical-align: middle;/>

④ <img class=jc-formula data-tex=\frac { 1 }{ n-1 } \sum _{ i=1 }^{ n-1 }{ { X }_{ i } } src=https://huaweicloudobs.ahjxjy.cn/1C176141AB6A855E8CFD52AEF5D595C0.png style=vertical-align: middle;/>

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【单选题】令前提: <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xF(x)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />y((F(y)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee /> G(y))<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> R(y)), <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xF(x)，则下面不是其有效结论的是：

① <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xR(x)

② <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />y((F(y) <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee /> G(y))<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> R(y))

③ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />x(F(x)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee /> G(x))

④ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />x(F(x)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee /> G(x))

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【单选题】设<img class=jc-formula data-tex=\xi \~ N(\mu ,{ \sigma }^{ 2 }) src=https://huaweicloudobs.ahjxjy.cn/2147D5A5BB1BD04932F9A62490D99E10.png style=vertical-align: middle;/>，其中<img class=jc-formula data-tex=\mu \quad src=https://huaweicloudobs.ahjxjy.cn/72143C62DAAAA39AB69A5506838561CA.png style=vertical-align: middle;/>已知，<img class=jc-formula data-tex={ \sigma }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/0CF3AA226894411774EF0AB7244924B1.png style=vertical-align: middle;/>未知，<img class=jc-formula data-tex={ X }_{ 1 },{ X }_{ 2 },{ X }_{ 3 } src=https://huaweicloudobs.ahjxjy.cn/4FF77F2383FA30F4DFAC4C0C4AF2E219.png style=vertical-align: middle;/>为其样本，下列各项不是　统计量的是

① <img class=jc-formula data-tex=\frac { 1 }{ { \sigma }^{ 2 } } ({ X }_{ 1 }^{ 2 }+{ X }_{ 2 }^{ 2 }+{ X }_{ 3 }^{ 2 }) src=https://huaweicloudobs.ahjxjy.cn/BF31734B07ABA2B89563EB8446340FDB.png style=vertical-align: middle;/>

② <img class=jc-formula data-tex={ X }_{ 1 }+3\mu \quad src=https://huaweicloudobs.ahjxjy.cn/5192835F8320C3E0CCC7F57B09D42755.png style=vertical-align: middle;/>

③ <img class=jc-formula data-tex=max({ X }_{ 1 }{ ,X }_{ 2 },{ X }_{ 3 }) src=https://huaweicloudobs.ahjxjy.cn/920DB46E711859C1EF3DA8FA1D37AB7D.png style=vertical-align: middle;/>

④ <img class=jc-formula data-tex=\frac { 1 }{ 3 } ({ X }_{ 1 }+{ X }_{ 2 }+{ X }_{ 3 })\quad src=https://huaweicloudobs.ahjxjy.cn/BEACA87C54812DAB7578055979EAA505.png style=vertical-align: middle;/>

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【单选题】设前提: p<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge /><img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg />q <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> r, p, q <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> s, <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg />s. 则下面哪个不是其有效结论：

① r

② <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg />q.

③ q<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto />p

④ q

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【单选题】令前提: <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />x(F(x)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /> (G(a) <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />R(x))), <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xF(x)，则下面不是其有效结论的是：

① <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />x(F(x) <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />R(x))

② G(a)

③ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />xR(x)

④ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xR(x)

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【单选题】令前提: <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />x(F(x) <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee />G(x)), <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg /><img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xG(x)，则下面不是其有效结论的是：

① <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />xF(x)

② <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />x<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg /> G(x)

③ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/151E88A53D653382F547CC2EA5D9CEBC.png data-tex=\forall />xF(x)

④ <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/117E6A630A0200497B87D15B90307923.png data-tex=\exists />x(F(x)<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/7BA9C8923F2F9C5684519175C6A722C4.png data-tex=\vee /> G(x))

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【判断题】当<img class=jc-formula data-tex={ \sigma }^{ 2 } src=https://huaweicloudobs.ahjxjy.cn/F82DC67D9EBCC9F258673A10C47B1E61.png style=vertical-align: middle;/>已知时，正态总体均值<img class=jc-formula data-tex=\mu src=https://huaweicloudobs.ahjxjy.cn/76B82DDD82B6A5E433B15031AB645605.png style=vertical-align: middle;/>的90%的置信区间的长度为<img class=jc-formula data-tex=2{ \mu }_{ 0.05 }\frac { \sigma }{ \sqrt { n } } src=https://huaweicloudobs.ahjxjy.cn/7BB020021DF564D73E238D17B333D133.png style=vertical-align: middle;/>

① 正确

② 错误

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【单选题】公式“<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg /> (q<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/F388E7EE9892B38FECEEB653227F230A.png data-tex=\mapsto /><img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg />p) <img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge /><img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/09825764C15E56B1CFE3099F64BC5193.png data-tex=\neg />p”的主合取范式为:

① M0.

② M0<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M1

③ M0<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M1<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M2

④ M0<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M1<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M2<img class=jc-formula style=vertical-align: middle; src=https://huaweicloudobs.ahjxjy.cn/D50FEE5510C853C83F78D440017D8E6B.png data-tex=\wedge />M3.

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随机题目

【单选题】 Last month, the little girl _______ well enough by the neighbors while her parents were volunteering.

① is cared for

② was cared for

③ will be cared for

④ cares for

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【单选题】 ______ a year does your school have sports meeting?Twice a year.

① How often

② How soon

③ How long

④ How many times

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【单选题】 Don’t worry. We have _______ to finish the work carefully.

① enough time

② less time

③ little time

④ few times

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【单选题】 ______ either you or I good at drawing?

① Am

② Are

③ Is

④ Do

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【单选题】 The room ______ as a meeting room.

① used to being used

② was used to being used

③ used to be used

④ was used to be used

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【单选题】 Don’t _______ our hopes. As long as we pull together, we’ll make it.

① give up

② give out

③ give back

④ give away

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【单选题】 Every morning, Tim often sees groups of middle-aged women _______ in the square.

① dance

② to dance

③ dances

④ danced

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【单选题】 We decided to _______ to help the sick children with their homework.

① go to the hospital

② went to a hospital

③ going to a hospital

④ went to the hospital

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【单选题】 You should _______ your shoes before you enter the dancing room.

① get off

② put off

③ take off

④ fall off

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【单选题】 There are ________ people in front of the cinema gate so we have to wait ________ time to get into the cinema.

① too much; much too

② too many; too much

③ much too; too much

④ too much; too many

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