A sample of 50 items has a mean weight of 20 grams. If the standard deviation is 2 grams, what is the confidence interval for the population mean at a 95% confidence level? A. (19.2, 20.8) B. (18.5, 21.5) C. (19.5, 20.5) D. (19.0, 21.0) ...
A. Most of the people in the sample group are between 22 and 28 years old. B. All of the people in the sample group are 25 years old. C. Half of the people in the sample group are younger than 22 years old. D. None of the above. ...
【题目】If the mean and standard deviation of a dataset are given, which data set has a variance equal to 16?(A. Mean = 4 ; Standard Deviation = sB. Mean = 256; Standard Deviation = sC. Mean=4; Standard D evatinα=256D. Mean = 256; Standard Deviation = 4 ...
If a certain sample of data has a mean of 20 and a standard deviation of 3, which of the following values is more than 2.5 standard deviations from the mean?A. 12.0B. 13.5C. 17.0D. 23.5E. 26.5我根本就一点都不懂方差, 除了公式! 这句话什么意思? 怎么算?谢谢! 相关知识点: 试题...
A list of numbers has a mean of a standard deviation of 2.5.If x is a number in the list that is 2 standard deviations above the mean,what is the value of 这是新GRE官方指南上149页的一道题啊,不好意思,开头是...has a means of 8 and a standard deviation......
If a certain sample of data has a mean of 20 and a standard deviation of 3, which of the following values is more than 2.5 standard deviations from the mean?A. 12.0B. 13.5C. 17.0D. 23.5E. 26.5我根本就一点都不懂方差, 除了公式! 这句话什么意思? 怎么算?谢谢! 扫码下载作业帮搜索答疑...
If the mean is 40 and the standard deviation is 7, what is the z-score of the number 50? 相关知识点: 试题来源: 解析 The -score must be between 1 and 2\ (since)\ 40+7=47 would have a z-score of 1 while 40+2⋅ 7=54 would have a -score of 2. Use the formula: = (...
原题是:“A list of numbers has a mean of 8 and a standard deviation of 2.5.If x is a number in the list that is 2 standard deviations above the mean,what is the value of ”能说一下具体怎么写,我感觉没看懂这道题...是一道GRE数学题... 扫码下载作业帮搜索答疑一搜即得 答案解析 查看更...
A researcher computed the mean, the median, and the standard deviation for a set of performance scores. If 5 were to be added to each score, which of these three statistics would change? 选项: A、 The mean only B、 The median only C、 The standard deviation only D、 The mean and the...
百度试题 结果1 题目【题目】If X is a normal random variable with a mean of 50 and a standard deviation of 5,find thevalue of c. such thatp(X≥c)≅0.95 相关知识点: 试题来源: 解析 【解析】41.7757 反馈 收藏