look in a maths dictionary
The formula to calculate the variance of a set of data is given by: [ \sigma^2 = \frac{1}{N} \sum_{i=1}^{N} (x_i - \mu)^2 ] for a population, where ( \sigma^2 ) is the variance, ( N ) is the number of data points, ( x_i ) represents each data point, and ( \mu ) is the mean of the data set. For a sample, the formula adjusts to: [ s^2 = \frac{1}{n-1} \sum_{i=1}^{n} (x_i - \bar{x})^2 ] where ( s^2 ) is the sample variance, ( n ) is the number of sample points, and ( \bar{x} ) is the sample mean.
The variance is 27.0
The variance for 3 5 12 3 2 is: 16.5
There are 7 variances associated with a budget ( which are generally calculated for controlling purposes) 1- Material Price variance 2- Material Quantity variance 3- Labor rate variance 4- Labor efficiency variance 5- Spending variance 6- Efficiency variance 7- Capacity variance
Variance is std dev squared. Therefore, if std dev = 12.4, variance = 12.4^2 = 153.76.
You need to use the variance and covariance functions in Excel 1. Calculate the covariance of the stock returns with respect to an index 2. Calculate the variance of the index 3. Divide the first number by the second. See the related link for a spreadsheet
To efficiently calculate and visualize the plot covariance matrix in Python, you can use the NumPy library to calculate the covariance matrix and the Seaborn library to visualize it. First, import the necessary libraries: import numpy as np import seaborn as sns Next, calculate the covariance matrix using NumPy: data = np.random.rand(10, 2) # Example data cov_matrix = np.cov(data.T) Finally, visualize the covariance matrix using Seaborn: sns.heatmap(cov_matrix, annot=True, cmap='coolwarm', xticklabels=['Feature 1', 'Feature 2'], yticklabels=['Feature 1', 'Feature 2']) This will create a heatmap visualization of the covariance matrix with annotations showing the values.
See related link. You can use Excel, if you dataset is not too big. Generally, if I have a table of data, with n columns corresponding to n variables with N observations, I can calculate the covariance of columns a and b, using excel covar function, covar(range of first data values, range of second data values) To keep things organized, you may want to name the ranges of your columns and use them as the arguments in the covar.
[((.39)^2)*160 +((.61)^2)*340+2*.61*.39*190]^.5 = 15.5323
Beta is calculated by comparing the returns of a stock to the returns of a benchmark index, typically the S&P 500. The formula for beta is: [ \beta = \frac{\text{Covariance}(\text{Stock Returns}, \text{Market Returns})}{\text{Variance}(\text{Market Returns})} ] For example, if a stock has a covariance with the market of 0.02 and the variance of the market returns is 0.01, the beta would be calculated as 0.02 / 0.01 = 2. This indicates that the stock is twice as volatile as the market.
[N*(N-1)]/2 N=1700 (1700*1699)/2 = 1,444,150 Covariance
This years' sales plus last years' sales divided by 2
The formula to calculate the variance of a set of data is given by: [ \sigma^2 = \frac{1}{N} \sum_{i=1}^{N} (x_i - \mu)^2 ] for a population, where ( \sigma^2 ) is the variance, ( N ) is the number of data points, ( x_i ) represents each data point, and ( \mu ) is the mean of the data set. For a sample, the formula adjusts to: [ s^2 = \frac{1}{n-1} \sum_{i=1}^{n} (x_i - \bar{x})^2 ] where ( s^2 ) is the sample variance, ( n ) is the number of sample points, and ( \bar{x} ) is the sample mean.
Variance = sigma((value - mean)2) / (# values - 1) Mean = (0+1+1+2)/4 = 1 Variance = ((0-1)2+(1-1)2+(1-1)2+(2-1)2)/(4-1) Variance = (1+0+0+1)/3 Variance = 2/3 Variance ~ 0.667
Degrees of freedom in the context of covariance typically refer to the number of independent values that can vary in the calculation of the covariance between two variables. When calculating sample covariance, the degrees of freedom are often adjusted by subtracting one from the sample size (n-1) to account for the estimation of the mean values from the same data set. This adjustment helps provide a more accurate estimate of the population covariance. Therefore, the degrees of freedom for covariance in a sample of size n is generally n-2, as both variables' means are estimated from the data.
The variance of 2 3 5 12 = 20.3333
The variance is 27.0