空小藏 · 2019年10月30日
问题如下：
Assuming the height of a tree in a forest follows a normal distribution, there are more than 10,000 trees. The sample size of test is 200, the 95% confidence interval of the sample mean of the height is 11 to 35 meters based on a z-statistic, the standard error of mean height is closest to:
选项：
A.1.96.
B.3.58.
C.6.12.
D.10.50.
解释：
C is correct.
考点：The central limit theorem (CLT)
解析：95%的置信区间是11到 35，z值是1.96.
平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准差。23+1.96sx等于35，sx等于6.12米
这题出错了吧
NO.PZ2019040801000025 问题如下 Assuming the height of a tree in a forest follows a normstribution, there are more th10,000 trees. The sample size of test is 200, the 95% confinintervof the sample meof the height is 11 to 35 meters baseon a z-statistithe stanrerror of meheight is closest to: A.1.96. B.3.58. C.6.12. 10.50. C is correct.考点The centrlimit theorem (CLT)解析95%的置信区间是11到 35，z值是1.96.平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准误。23+1.96sx等于35，sx等于6.12米 如题，请老师赐教，盼复，谢谢
NO.PZ2019040801000025 问题如下 Assuming the height of a tree in a forest follows a normstribution, there are more th10,000 trees. The sample size of test is 200, the 95% confinintervof the sample meof the height is 11 to 35 meters baseon a z-statistithe stanrerror of meheight is closest to: A.1.96. B.3.58. C.6.12. 10.50. C is correct.考点The centrlimit theorem (CLT)解析95%的置信区间是11到 35，z值是1.96.平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准误。23+1.96sx等于35，sx等于6.12米 题目没有提到ranmly select，另外sample mean是在11和35之间，求出来的为什么不是sample s直接就是标准误？
NO.PZ2019040801000025问题如下Assuming the height of a tree in a forest follows a normstribution, there are more th10,000 trees. The sample size of test is 200, the 95% confinintervof the sample meof the height is 11 to 35 meters baseon a z-statistithe stanrerror of meheight is closest to:A.1.96.B.3.58.C.6.12.10.50.C is correct.考点The centrlimit theorem (CLT)解析95%的置信区间是11到 35，z值是1.96.平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准误。23+1.96sx等于35，sx等于6.12米看过之前类似提问，感觉没说清楚
NO.PZ2019040801000025 问题如下 Assuming the height of a tree in a forest follows a normstribution, there are more th10,000 trees. The sample size of test is 200, the 95% confinintervof the sample meof the height is 11 to 35 meters baseon a z-statistithe stanrerror of meheight is closest to: A.1.96. B.3.58. C.6.12. 10.50. C is correct.考点The centrlimit theorem (CLT)解析95%的置信区间是11到 35，z值是1.96.平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准误。23+1.96sx等于35，sx等于6.12米 如题
NO.PZ2019040801000025问题如下Assuming the height of a tree in a forest follows a normstribution, there are more th10,000 trees. The sample size of test is 200, the 95% confinintervof the sample meof the height is 11 to 35 meters baseon a z-statistithe stanrerror of meheight is closest to:A.1.96.B.3.58.C.6.12.10.50.C is correct.考点The centrlimit theorem (CLT)解析95%的置信区间是11到 35，z值是1.96.平均数为0.5*（11+35）=23.所以置信区间是23 ± 1.96sx, sx是标准误。23+1.96sx等于35，sx等于6.12米老师，这个样本（容量200）的均值为什么是（11+35）/2呢？如果这么算不就相当样本容量2棵树，一颗高度11，一颗高度35？
