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...
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
Answer and Explanation: The answer is (c). (c) Interquartile range (IQR) is less likely to be affected by outliers, and it is one of the measures of variability. IQR implies...
Normal distribution has mean μ = 250 and standard deviation σ = 20. Find the 70% percentile for this distribution. Normal Distribution: The normal distribution is used to calculate the percentile rank from the z-score value. The z-score value is...
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
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 scor...
The median is a measure of central tendency, used for samples, frequency distributions and probability distributions also have it. In these cases, it is useful to remember that the median is also the lower 50th percentile.Answer and Explanation: The median i...
Answer to: Find the mean and variance for the following pdf : f (x) = 1.5 x^2 for -1 less than x less than 1. Also find the cdf F (x) corresponding...
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...
(b) What score is at the 15th percentile?True or false? The standard error of estimate gives the average deviation of prediction errors around the correlation line.If you add (or subtract) the same number of points to all the score...