【多选题】
Which three features can be enabled for a new host cluster? (Choose three.)___
A. Storage Distributed Resource Scheduling
B. High Availability
C. Fault Tolerance
D. Distributed Resource Scheduling
E. Virtual SAN
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相关试题
【多选题】
An administrator receives a report that no real time statistics are available for a virtual machine in the vCenter Server inventory. Which two statements indicate likely causes of the problem? (Choose two.)___
A. The virtual machine is powered off.
B. The host containing the virtual machine is disconnected from vCenter Server.
C. There is insufficient real time data to display the information.
D. The vCenter Server service is not running.
【多选题】
Your manager has given you a bash script that retrieves data for ESXi 6.x host configurations. This data needs to be collected right after the installation of a host and must be run directly on the host. Which two actions can be used to run this script on an ESXi host? (Choose two.)___
A. Connect to the host with Ruby vSphere Console and run the script from there.
B. Enable SSH access from the Direct Console User Interface.
C. Enable the ESXi Shell from the
D. irect Console User Interface.
【多选题】
Which two are true about the Risk badge in vRealize Operations? (Choose two.)___
A. The Risk badge indicates potential future problems that may degrade the performance of the system.
B. Risks may require attention in the near future.
C. The Risk badge indicates problems that are degrading performance of the system.
D. Risks require attention now to correct system performance problems.
【多选题】
vSphere Update Manager allows which two virtual machine attributes to be upgraded? (Choose two.)___
A. Virtual machine firewall policies for NSX.
B. Software Packages in the virtual machine.
C. Virtual machine Hardware Version.
D. VMware Tools Upgrade.
【多选题】
What are two benefits of using NFS 4.1 with vSphere 6.x as compared to NFS 3? (Choose two.)___
A. NFS 4.1 supports Kerberos Authentication
B. NFS 4.1 supports multipathing
C. NFS 4.1 supports IPv6
D. NFS 4.1 supports hardware acceleration
【多选题】
Which three statements are true regarding Fault Tolerance? (Choose three.)___
A. Applications need to be continuously available to users.
B. Applications without native clustering capabilities can be protected.
C. Custom clustering solutions are complicated to configure and maintain.
D. Applications that have 16 vCPUs are supported.
E. Prevents application crashes by analyzing the workload and correcting problems.
【多选题】
Which two statements are true regarding VMware vSphere Flash Read Cache (vFRC)? (Choose two.)___
A. Cache fills and cache evictions happen in the granularity of a cache block size.
B. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying storage.
C. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying cache data.
D. Cache fills and cache evictions happen in the granularity of the disk block size.
【多选题】
What are two possible causes of Storage Distributed Resource Scheduler (SDRS) being disabled on one or more virtual machine disks in a datastore cluster? (Choose two.)___
A. The virtual machine has vSphere Fault Tolerance disabled.
B. The virtual machine is a template.
C. The virtual machine swap file is on a shared datastore.
D. The disk is a CD-ROM/ISO file.
【多选题】
An administrator attempts to install vCenter Single Sign-On Server. The installer returns an error message indicating that the installation failed. Prior to the installation, all setup prerequisites were met. The administrator has generated a vCenter Server Single Sign-On support bundle. Which two files should the administrator analyze to determine the cause of the failure? (Choose two.)___
A. Server\utils\logs\imsTrace.log
B. Server\utils\logs\install.txt
C. %TEMP%\utils\logs\vminst.log
D. %TEMP%\vminst.log
【多选题】
An administrator is unable to remove an ESXi 6.x host from a vSphere Distributed Switch. What are two likely reasons for this issue? (Choose two.)___
A. Vmkernel interfaces on the switch are still in use.
B. VM Network port group adapters are connected to different switch.
C. Physical NICs are migrated to different switch.
D. VM Network adapters are connected to this switch.
【多选题】
Which two Identity Sources are available to add for vCenter Single Sign-On authentication? (Choose two.)___
A. LocalOS
B. OpenLDAP
C. NIS as an LDAP Server
D. VCMSDS
【多选题】
What are three goals of resource management within a cluster? (Choose three.)___
A. To prevent virtual machines from monopolizing resources and to guarantee predictable service rates.
B. To exploit undercommitted resources and overcommit with graceful degradation.
C. To provide solutions to potential problems that you might encounter when using vCenter Server.
D. To control the relative importance of virtual machines and provide flexible dynamic partitioning.
E. To provide additional network administration capabilities.
【多选题】
Which three actions can be taken as a result of executing the vSphere Update Manager 6.x scan and remediation wizards? (Choose three.)___
A. Install and upgrade software in virtual machines.
B. Upgrade the firmware on ESXi host devices.
C. Upgrade and Patch ESXi hosts.
D. Install and update third-party software on hosts.
E. Upgrade virtual machine hardware.
【多选题】
Which two statements are true about deploying and using vSphere Replication? (Choose two.)___
A. ESXi hosts managed by a single vCenter Server instance require a connection between the two vSphere Replication appliances.
B. Sites managed by different vCenter Server instances require a connection between the two vSphere Replication appliances.
C. Sites managed by different vCenter Server instances require the use of Site Recovery Manager and a connection between the two vSphere Replication appliances.
D. ESXi hosts managed by a single vCenter Server instance require a single vSphere Replication appliance.
【多选题】
An administrator is attempting to power on a virtual machine, but the task is hanging at 95%. What three scenarios best explain why this problem is happening? (Choose three.)___
A. A virtual machine question is currently being posed to the administrator.
B. Another task for the virtual machine or other component is already in progress.
C. The VMware High Availability cluster has insufficient resources to guarantee failover.
D. The host has lost access to the storage device containing the virtual machine files.
E. The host is under resource contention and unable to power on the virtual machine.
【多选题】
Which three features are not supported when using Fault Tolerance in vSphere 6.x? (Choose three.)___
A. Virtual Volumes (VVOLS)
B. Storage vMotion
C. Virtual Machine Component Protection
D. vMotion
E. vSphere Distributed Switches
【多选题】
Which two storage controller configurations can be used with Virtual SAN? (Choose two.)___
A. SAS controllers in Passthrough mode
B. SAS controllers in RAID0 mode
C. SAS controllers in RAID1 mode
D. SAS controllers in RAID10 mode
【多选题】
Which three are requirements when using vMotion to move a virtual machine across vCenter Server systems? (Choose three.)___
A. Both vCenter Servers must be using Enhanced Linked Mode.
B. Both vCenter Servers must be in the same Single Sign-On Domain.
C. Time must be synchronized.
D. Duplicate VM MAC addresses must be configured.
E. Both vCenter Servers must have High Availability enabled on source and destination clusters.
【多选题】
Which two components can be used when configuring Enhanced Linked Mode? (Choose two.)___
A. vCenter Server Appliance
B. vRealize Operations Manager
C. vSphere Management Appliance
D. vCenter Server for Windows
【多选题】
An organization has a number of virtual machines that would benefit from Fault Tolerance. These include: <A single vCPU Apache Server> < A dual vCPU vCenter Server> < A quad vCPU SQL Server> <An eight vCPU Hadoop Server>. Which two virtual machines can be configured to use VMware Fault Tolerance? (Choose two.)___
A. Apache Server
B. vCenter Server
C. SQL Server
D. Hadoop Server
【多选题】
Which two badges are major badges in vRealize Operations? (Choose two.)___
A. Risk
B. Efficency
C. Workload
D. Faults
【多选题】
An administrator is deploying multiple Windows 2003 Virtual Machines from the same template. What two steps should be taken to avoid network conflicts? (Choose two.)___
A. Customize the guest operating system.
B. Install VMware Tools into the new virtual machines.
C. Copy the Microsoft Sysprep tools onto the vCenter Server system.
D. Ensure the e1000 vmnic is selected for each new virtual machine.
【多选题】
Which three conditions would prevent Storage I/O Control from being enabled on a group of datastores? (Choose three.)___
A. The datastores planned for the solution are used by different vSphere clusters.
B. A datastore planned for the solution is configured as a Raw Device Mapping file.
C. A datastore planned for the solution has three extents.
D. A datastore planned for the solution is configured as NFS.
E. The organization has an Enterprise license.
【多选题】
Which two actions are prerequisites to adding ESXi 6.x hosts to a vSphere Distributed Switch? (Choose two.)___
A. Verify that there is at least one Distributed Port Group on the Distributed Switch.
B. Verify that the Distributed Port Group have active uplinks configured in its teaming and failover policy.
C. Verify that the
D. istributed Switch has been configured with a Network Profile.
【多选题】
An organization has configured Distributed Power Management (DPM) on a vSphere 6 cluster. The organization wants to be alerted when an ESXi host has been powered down by DPM. Which two options represent the type and name of the alarm that would accomplish this? (Choose two.)___
A. DrsEnteringStandbyModeEvent
B. DrsEnteredStandbyModeEvent
C. Event-based
D. Condition-based
【多选题】
Which two allow for the disabling of Network Rollback operations? (Choose two.)___
A. Modifying the vpxd advanded configuration options and adding the config.vpxd.network.rollback key
B. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\vpxd.cfg file and adjusting the<rollback> xml tag
C. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\vpxd.cfg file and adjusting the <networkrollback> xml tag
D. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\firstboot\vpxd-service- spec.prop file and adjusting the <rollback> xml tag
【多选题】
An administrator is tasked with performing a vMotion migration of a virtual machine. The virtual machine is configured as follows: <vSphere Flash Read Cache (vFRC) enabled> <Is part of a Distributed Resource Cluster (DRS) Cluster> Which two statements are true? (Choose two.)___
A. Each ESXi host in the cluster supports multiple virtual flash resources.
B. Each ESXi host in the cluster supports one virtual flash resource.
C. DRS treats powered-on virtual machines with Flash Read Cache as having a preferred affinity to their current host and moves them only for mandatory reasons.
D. DRS treats powered-on virtual machines with Flash Read Cache as having a required affinity to their current host and does not move them.
【多选题】
An administrator is using the Host Failures to Tolerate Admission Control Policy for a vSphere High Availability ___ cluster. When configuring this setting on the cluster, the administrator sees this error message: <Insufficient resources to satisfy HA failover level on cluster > What are two likely causes for the error? (Choose two.)(AB)
A. The hosts in the cluster are disconnected.
B. A host in the cluster is displaying an HA error.
C.
D. istributed Resource Scheduler has not been configured on the cluster.
【多选题】
What are two ways to identify TCP/IP stack information? (Choose two.)___
A. Using the vSphere Web Client
B. Using esxcli network ip netstack
C. Using esxcfg-netstack
D. Using the vSphere Client
【多选题】
Which two actions are required when enabling vFlash Read Cache for a virtual machine's virtual disk? (Choose two.)___
A. A value in the Virtual Flash Read Cache text box must be entered.
B. A Flash Resource Pool for Cache size reservation must be entered.
C. The Device backing and the block size must be configured.
D. The
E. nable virtual flash host swap cache check box must be selected.
【多选题】
What two IT infrastructure components are virtualized by vSphere Essentials? (Choose two.)___
A. Networks
B. Applications
C. Storage
D. Management
【多选题】
When attempting to access a virtual machine, an administrator is unable to login using the vSphere credentials. What two options are probable causes of the authentication failure? (Choose two.)___
A. The vSphere credentials have not been granted permissions.
B. The vSphere credentials are granted read-only permissions.
C. The vSphere credentials are granted no-access permissions.
D. The vSphere credentials are not a member of the local administrator group.
【多选题】
An administrator is performing a scripted installation of ESXi 6.x. In which three locations does the script need to be? (Choose three.)___
A. PXE Server
B. HTTPS
C. FTP
D. NFS
E. VVOLs Datastore
【多选题】
In order for a company to meet regulatory requirements, all ESXi 6.x Hosts must be configured to direct logs to a syslog server. What are two ways ESXi hosts can configured for this action? (Choose two)___
A. Use the esxcli system syslog command.
B. Edit them in the ESXi host Advanced System Settings.
C. From the Syslog collector user interface of the Web Client.
D. Syslog logging is not available for
E. SXi Hosts.
【多选题】
Which three actions can be executed when an alarm is triggered? (Choose three.)___
A. Send an email.
B. Send an SNMP trap.
C. Run a script or command.
D. Run an Orchestrator workflow.
E. Send a trigger to syslog.
【多选题】
An administrator is attempting to power on a virtual machine, but is unable to do so. Which two reasons are probable causes of the failure? (Choose two.)___
A. Storage access to the virtual machine swap file has been lost.
B. One of the virtual machine VMDK files is locked.
C. Virtual machine is running CentOS 7.0 64-bit.
D. Virtual machine has Hyper-Threading enabled.
【多选题】
An administrator has configured a host profile so that ESXi 6.x hosts will point to the corporate NTP server for time synchronization. The NTP server is located at 10.0.30.213, but time has not been synchronized properly across the ESXi hosts. The administrator reviews Host Profile settings as shown in the Exhibit. Which two steps are required to resolve the issue? (Choose two.)___
A. Correct the NTP server IP address.
B. Check the host for host profile compliance.
C. Remediate the host based on the updated host profile.
D. Change the NTP server to the FQDN as IP Addresses are not supported.
【多选题】
An administrator is attempting to migrate a large Hadoop virtual machine using vMotion. The administrator notices a delay when the machine is quiesced. The Hadoop virtual machine is processing many transactions a second to an in-memory database. Which two actions would help reduce the amount of time needed to perform a vMotion on this virtual machine? (Choose two.)___
A. Use multiple NICs for the vMotion vmkernel port.
B. Use a 10Gbps Network card for the vMotion vmkernel port.
C. Add an additional management network to help transmit the data quicker.
D. Disable Fault Tolerance before performing the vMotion.
【多选题】
An administrator is installing a new network card in an ESXi 6.x host that is part of a vSphere cluster. When the host is placed into maintenance mode, the vSphere Web Client displays the progress bar at 2% for over 30 minutes. Which two are likely reasons for this occurrence? (Choose two.)___
A. Maintenance mode is unable to migrate all virtual machines from the host.
B. There is a large number of virtual machines that must be migrated from the host.
C. VMware High Availability is in the process of reconfiguring the cluster.
D. Each virtual machine on the
E. SXi host must be reconfigured to recognize the new adapter.
【多选题】
Which two events happen when Distributed Resource Scheduler (DRS) is disabled? (Choose two.)___
A. The cluster's resource pool heirarchy and affinity rules are re-established when DRS is turned back on.
B. The cluster's resource pool hierarchy and affinity rules are not re-established when DRS is turned back on.
C. The cluster's resource pools are removed from the cluster.
D. The cluster's resource pools are removed from the cluster and assigned to the hosts.
推荐试题
【单选题】
在有截距项的三元线性回归模型中,若辅助回归X_i3=α_0+α_1 X_i1+α_2 X_i2+v_i ,i=1,2,⋯,n,且其中常数α_0,α_1,α_2不全为0,v_i不全为0,则表明___
A. 数据矩阵X的第四列与前三列存在完全多重共线性
B. 数据矩阵X的第四列与前三列存在不完全多重共线性
C. 数据矩阵X的第四列与前三列不存在多重共线性
D. 解释变量X_1,X_2,X_3之间存在不完全多重共线性
【单选题】
在有截距项的三元线性回归模型中,若辅助回归X_i3=α_0+α_1 X_i1+α_2 X_i2+v_i ,i=1,2,⋯,n,且其中常数α_0,α_1,α_2全为0,则表明___
A. 数据矩阵X的第四列与前三列存在完全多重共线性
B. 数据矩阵X的第四列与前三列存在不完全多重共线性
C. 数据矩阵X的第四列与前三列不存在多重共线性
D. 解释变量X_1,X_2,X_3之间存在完全多重共线性
【单选题】
则表明___
A. 数据矩阵X的第四列与前三列不存在严重不完全多重共线性
B. 数据矩阵X的第三列与其它三列存在严重不完全多重共线性
C. 数据矩阵X的第四列与前三列之间的不完全多重共线性比X的第三列与其它三列之间的不完全多重共线性更严重
D. 解释变量X_1,X_2,X_3之间存在不完全多重共线性
【单选题】
在有截距项的三元线性回归模型中,若辅助回归X_i3=α_0+α_1 X_i1+α_2 X_i2+v_i ,i=1,2,⋯,n,且其中常数α_0,α_1,α_2不全为0,v_i全为0,则表明___
A. 模型参数的OLS估计不存在
B. β_3 的OLS估计不存在
C. β_3 的OLS估计有无穷多
D. Var(β ̂_3)趋于无穷大
【单选题】
则___
A. β_3 的OLS估计不存在
B. Var(β ̂_3)一定很大
C. β_3的t检验一定显著为0
D. 在显著性水平0.05下,如果β_3的t检验显著不为0,则〖P(β〗_3=0)≤0.05
【单选题】
与前三列正交时,参数的OLS估计记为γ ̂_0,γ ̂_1,γ ̂_2,γ ̂_3,则___
A. β_3 的OLS估计不存在
B. Var(β ̂_3)一定很大
C. Var(β ̂_3 )=20Var(γ ̂_3 )
【单选题】
线性模型Yi=β0+β1X1i+β2X2i+μi不满足哪一假定称为异方差现象?___
A. Cov(μi,μj)=0
B. Var(μi)=σ2
C. Cov(Xi,μi)=0
D. Cov(X1i,X2i)=0
【单选题】
加权最小二乘法克服异方差的主要原理是通过赋予不同误差的观测点以不同的权数,以提高估计精度,即:___
A. 重视大误差的作用,轻视小误差的作用
B. 重视小误差的作用,轻视大误差的作用
C. 重视小误差的作用,更重视大误差的作用
D. 轻视大误差的作用,更轻视小误差的作用
【单选题】
异方差性条件下普通最小二乘估计量是___
A. 无偏估计量
B. 有偏估计量
C. 有效估计量
D. 最佳无偏估计量
【单选题】
如果戈德菲尔德—匡特检验显著,则认为什么问题是严重的___
A. 异方差问题
B. 异常值
C. 变量关系非线性
D. 规律性扰动
【单选题】
经验认为,某个解释变量与其它解释变量间多重共线性严重的情况是这个解释变量的 ___
A. 大于1
B. 小于1
C. 大于10
D. 小于5
【单选题】
如果戈里瑟检验表明,普通最小二乘估计结果的残差 与 显著有关系|e_i |=2x_i+v_i,其中( 满足线性模型的全部经典假设),则用加权最小二乘法估计模型参数时,∑▒〖w_i e_i^2 〗中的权数w_i应取为___
A.
B.
C.
D.
【单选题】
DW的取值范围是:___
A. -1≤DW≤0
B. -1≤DW≤1
C. -2≤DW≤2
D. 0≤DW≤4
【单选题】
根据20个观测值估计的结果,一元线性回归模型的DW=2.6,在α=0.05的显著性水平下查得样本容量n=20,解释变量k=1个时,dL=1.20,dU=1.41,则可以判断:___
A. 不存在一阶自相关
B. 存在正的一阶自相关
C. 存在负的一阶自相关
D. 无法确定
【单选题】
根据样本资料建立某消费函数如下: =100.50+0.45Xt+55.35D,其中C为消费,X为收入,虚拟变量D= ,所有参数均检查显著,则城市的消费函数为:___
A. =155.85+0.45Xt
B. =100.50+0.45Xt
C. =100.50+55.35D
D. =100.95+55.35D
【单选题】
根据样本资料建立的消费函数为 ,其中为消费,为收入,虚拟变量 ,所有参数均检验显著,则城镇家庭消费函数估计式为___
A.
B.
C.
D.
【单选题】
设消费函数为 ,其中虚拟变量 ,当统计检验表明下列哪项成立时,表示城镇家庭与农村家庭有一样的消费行为___
A.
B.
C.
D.
【单选题】
使用多项式方法估计有限分布滞后模型时,多项式 i=α0+α1i+α2i2…αnim的阶数m的确定方法为___
A. 事先给定
B. 通过逐步计算确定
C. 由模型自动生成
D. 随意定
【单选题】
对于模型:Yt=α+β0Xt+β1Xt-1+β2Xt-2+…+βiXt-i+μt,如果有βi=β0λi,0<λ<1,则称原模型为:___
A. 变参数模型
B. 有限分布滞后模型
C. 有限多项式滞后模型
D. 考伊克模型
【单选题】
在估计分布滞后模型参数时,一般是对分布滞后模型施加约束条件,以便减少模型中的参数。以下约束条件中,错误的是___
A. 系数值βi先增加后下降
B. 系数值βi先下降后增加再下降
C. 系数值βi按几何级数增加
D. 系数值βi按几何级数衰减
【单选题】
下面关于内生变量的表述,错误的是___
A. 内生变量都是随机变量
B. 内生变量受模型中其它内生变量的影响,同时又影响其它内生变量
C. 在结构式方程中,解释变量可以是前定变量,也可以是内生变量
D. 滞后内生变量与内生变量具有相同性质
【单选题】
在结构式模型中,其解释变量___
A. 都是前定变量
B. 都是内生变量
C. 可以既有内生变量又有前定变量
D. 都是外生变量
【单选题】
联立方程模型中的非随机方程是:___
A. 行为方程
B. 技术方程
C. 制度方程
D. 平衡方程
【单选题】
第一个结构方程中的Y2是:___
A. 前定变量
B. 外生变量
C. 解释变量
D. 被解释变量
【单选题】
如果某个结构式方程是过度识别的,则估计该方程的参数可用___
A. 二阶段最小二乘法
B. 间接最小二乘法
C. 广义差分法
D. 最小二乘法
【单选题】
联立方程模型中,如果一个方程包含模型系统中的全部前定变量和内生变量,则这个方程___
A. 不存在识别问题
B. 过度识别
C. 恰好识别
D. 一定不可识别
【多选题】
经济计量模型主要应用于___
A. 经济预测
B. 经济结构分析
C. 评价经济政策
D. 政策模拟
E. 经济决策
【多选题】
经济计量学是哪三者的统一?___
A. 经济理论
B. 宏观管理
C. 统计学
D. 数学
E. 微观管理
【多选题】
利用普通最小二乘法求得的样本回归直线 具有以下特点___
A. 必然通过点( )
B. 残差ei的均值为常数
C. 的平均值与Yi的平均值相等
D. 残差ei与Xi之间存在一定程度的相关性
E. 不一定通过点( )
【多选题】
对于经典线性回归模型,0LS估计量具备------------------------___
A. 无偏性
B. 线性性
C. 正确性
D. 有效性
E. 可知性
【多选题】
当被解释变量的观测值Yi与回归值 完全一致时:___
A. 判定系数r2等于1
B. 判定系数r2等于0
C. 估计标准误差s等于1
D. 估计标准误差s等于0
E. 相关系数等于0
【多选题】
随机解释变量线性回归模型的基本假设中有___
A. 在解释变量取定一个样本的条件下u服从正态分布
B. 设计矩阵X列满秩
C. 解释变量存在二阶矩
D. 解释变量与u不相关
E. E(u)=0
【多选题】
在基本假设下,确定性解释变量线性回归模型参数的OLS估计具有性质___
A. E(β ̂)=β
B. 有效性
C. 一致性
D. 线性性
【多选题】
在基本假设下,随机解释变量线性回归模型参数的OLS估计具有性质___
A. E(β ̂|X)=β
B. β ̂=∑▒〖f(X) Y_i 〗
C. 一致性
D. 在满足AB两个性质的估计中,模型参数的OLS估计量在解释变量取定给定样本的条件下的条件方差最小
【多选题】
有预测Y ̂_0=β ̂_0+β ̂_1 X_01+β ̂_2 X_02+β ̂_3 X_03,Y ̃_0=γ ̂_0+γ ̂_1 X_01+γ ̂_2 X_02+γ ̂_3 X_03。则___。
A. 存在X_03=α_0+α_1 X_01+α_2 X_02,使〖Var(Y ̂〗_0)<〖Var(Y ̃〗_0);
B. 存在X_03=0,使〖Var(Y ̂〗_0)>〖Var(Y ̃〗_0);
C. 对任意X_0=(1,X_01,X_02,X_03)∈R^4,〖Var(Y ̂〗_0)<〖Var(Y ̃〗_0);
D. 对任意X_0=(1,X_01,X_02,X_03)∈R^4,〖Var(Y ̂〗_0)>〖Var(Y ̃〗_0)。
【多选题】
当数据矩阵存在严重不完全多重共线性时,下列阐述正确的是___
A. 预测方差变大
B. t=(Y ̂_f-E(Y_f))/(σ ̂√(X_f 〖(X^' X)〗^(-1) X_f^' )) 服从自由度为n-k+1的t分布,其中k为解释变量个数;
C. Y ̂_f-t_(α/2) (n-k+1) σ ̂√(X_f (X^' X)^(-1) X_f^' )≤E(Y_f )≤Y ̂_f+t_(α/2) (n-k+1)σ ̂√(X_f (X^' X)^(-1) X_f^' )
D. [Y ̂_f-t_(α/2) (n-k+1) σ ̂√(X_f (X^' X)^(-1) X_f^' ) ,Y ̂_f+t_(α/2) (n-k+1)σ ̂√(X_f (X^' X)^(-1) X_f^' )]包含
E. (Y_f )的概率为1-α。
【多选题】
下列阐述正确的是___
A. 增加样本容量可以减轻多重共线性;
B. 对确定性解释变量,增加样本容量可以使数据矩阵的多重共线性加强,也可以使数据矩阵的多重共线性减弱;
C. 对随机解释变量,增加样本容量只是使样本复相关系数取值于总体复相关系数附近的概率更大了,并不能肯定使样本复相关系数增加还是减小,即不能肯定使数据矩阵的多重共线性加强还是减弱;
D. 增加样本容量可以减小参数OLS估计的方差。
【多选题】
当Var(u_i )=σ_i^2 ,i=1,2,⋯,n不完全相同,但古典假定中其他假定仍满足时,下列阐述正确的是___
A. 参数的OLS估计仍具有线性性、无偏性,但不再是有效估计;
B. 参数的加权最小二乘估计具有效性;
C. 参数的加权最小二乘估计的方差小于或等于同一参数的OLS估计的方差;
D. 参数的OLS估计的方差大于同方差条件下同一参数的OLS估计的方差。
【多选题】
常用的检验异方差性的方法有___
A. 戈里瑟检验
B. 戈德菲尔德-匡特检验
C. 怀特检验
D. DW检验
【多选题】
当随机干扰项具有一阶自回归规律,但古典假定中其他假定仍满足时,下列阐述正确的是___
A. 参数的OLS估计仍具有线性性、无偏性,但不再是有效估计;
B. 参数的广义差分估计具有效性;
C. 参数的广义差分估计的方差小于或等于同一参数的OLS估计的方差;
D. 参数的OLS估计的方差大于古典假定条件下同一参数的OLS估计的方差。