Norms, like those presented on the Grade Level Charts, provide a measure of how students at a given percentile typically perform. Norms are not a judgment of what is good, bad, or acceptable, they simply indicate what is a typical performance at a given percentile. ...
6 概率统计之抽样分布一批材料,直径12cm,标准差0.04a.求随机选择直径小于12.08的概率b.求样本大小为16,直径小于12.08的概率c.find the 90% percentile for the sample mean distribution
Chapter 13/ Lesson 12 48K Discover the purpose of z-scores in statistics and learn the formula to find the z-score. Understand what positive and negative z-scores mean. Explore our homework questions and answers library Search Browse Browse by subject...
From the table, it’s easy to see how a single outlier can distort reality. A single value changes the mean height by 0.6m (2 feet) and the standard deviation by a whopping 2.16m (7 feet)! Hypothesis tests that use the mean with the outlier are off the mark. And, the much larger...
The other variant of the SD method is to use the Clever Standard deviation (Clever SD) method, which is an iterative process to remove outliers. In each iteration, the outlier is removed, and recalculate the mean and SD until no outlier is found. This method uses the threshold factor of ...
Answer to: Assume that the random variable X is normally distributed, with mean m = 50 and standard deviation s = 7. Find the 90th percentile for...
Answer to: Find the standard score (z-score) and the percentile of a data value which is 2.3 standard deviations below the mean. By signing up,...
The IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Find the 90th percentile of the IQ distribution. Hint: Using a normal table, Probability = 0.4500, Z = 1.645 sd. What is the population standard deviation if a s...
There is evidence that lower height is associated with a higher risk of coronary artery disease (CAD) and increased risk of type 2 diabetes (T2D). It is not clear though whether these associations are causal, direct or mediated by other factors. Here we
Find the mean mu, variance sigma^2, and standard deviation sigma of each distribution: (a) x 2 3 8 f(x) 1/4 1/2 1/4 (b) y -1 0 1 2 3 g(y) 0.3 0.1 0.1 0.3 0.2 For a normal distribution with mu = 100 and sigma = 15, wh...