how to calculate sxy in statistics?
529534
Sxy = (134 - 4 * 5.0 * 5.0 ) / ( n - 1) = 34 / 3 = 11.33. The slope of the regression line is b1 = Sxy / Sx^2, or b1 = 11.33 / 14 = 0.809. Thus the equation of the least squares line is yhat = 0.95 + 0.809 x.
513195
['Calculate the mean, x.', 'Write a table that subtracts the mean from each observed value.', 'Square each of the differences.', 'Add this column.', 'Divide by n -1 where n is the number of items in the sample This is the variance.']
648709
In statistics you'll come across slightly different notation than you're probably used to, but the math is exactly the same. The formula to find the sample mean is: = ( Σ xi ) / n. All that formula is saying is add up all of the numbers in your data set ( Σ means “add up” and xi means “all the numbers in the data set).
884202
['The mean value is calculated by adding all the data points and dividing by the number of data points.', 'The variance for each data point is calculated, first by subtracting the value of the data point from the mean. ... ', 'The square root of the variance—result from no.']
360517
['Find the difference each number is away from the mean, and then square that difference. For example, subtract 38 from 21 and then square the result. ... ', 'Add together the two values you calculated in the previous step. ... ', 'Divide your solution from the previous step by two since you have two observations.']
416155
To calculate standard deviation, add up all the data points and divide by the number of data points, calculate the variance for each data point and then find the square root of the variance.
24470
['Step 1: Find the mean.', 'Step 2: Subtract the mean from each score.', 'Step 3: Square each deviation.', 'Step 4: Add the squared deviations.', 'Step 5: Divide the sum by the number of scores.', 'Step 6: Take the square root of the result from Step 5.']
381214
['by converting the.', 'to a z-value and finding probabilities using the Z-table (see below). ... ', 'Substituting the appropriate values of the mean and standard error of.', 'the conversion formula becomes:', "Don't forget to divide by the square root of n in the denominator of z. ... ", 'As X has a normal distribution to start with, you know.']
425902
Step 3: Select the correct standard deviation There are two standard deviations listed on the calculator. The symbol Sx stands for sample standard deviation and the symbol σ stands for population standard deviation. If we assume this was sample data, then our final answer would be s =2.71.
1252459
['Calculate the mean (simple average of the numbers).', 'For each number: subtract the mean. ... ', 'Add up all of the squared results.', 'Divide this sum by one less than the number of data points (N - 1).']
864392
Use the formula SST – SSB to find the SSW, or the sum of squares within groups. Figure the degrees of freedom for between the groups, “dfb,” and within the groups, “dfw.” The formula for between groups is dfb = 1 and for the within groups it is dfw = 2n-2. Compute the mean square for the within groups, MSW = SSW / dfw.
1119052
['Calculate the mean (μ).', 'For each number, calculate the distance to the mean.', 'For each number, square this distance.', 'Sum (∑) these values.', 'Divide by the number of data points (N = 5).', 'Take the square root.', 'Fortunately, the STDEV. P function in Excel can execute all these steps for you.']
353571
['State the null and alternative hypotheses.', 'Specify α and the sample size.', 'Select an appropriate statistical test.', 'Collect data (note that the previous steps should be done prior to collecting data)', 'Compute the test statistic based on the sample data.']
38416
['First, take the square of the difference between each data point and the sample mean, finding the sum of those values.', 'Then, divide that sum by the sample size minus one, which is the variance.', 'Finally, take the square root of the variance to get the SD.']
546262
['First, determine n, which is the number of data values.', 'Second, calculate the arithmetic mean, which is the sum of scores divided by n. ... ', 'Then, subtract the mean from each individual score to find the individual deviations.', 'Then, square the individual deviations.']
372674
Take each number and subtract the mean, then square the result. Finally, divide by the length of the array and add that to your sum. The sum is the variance, and the square root of that is the standard deviation: double sd = 0; for (int i = 0; i < numbers.
1017854
['Gather the data. a. Select the subgroup size (n). ... ', 'Plot the data. a. ... ', 'Calculate the overall process averages and control limits. a. ... ', 'Interpret both charts for statistical control. a. ... ', 'Calculate the process standard deviation, if appropriate. a.']