how to calculate sample mean for grouped data?
234227
To calculate the mean of grouped data, the first step is to determine the midpoint (also called a class mark) of each interval, or class. These midpoints must then be multiplied by the frequencies of the corresponding classes. The sum of the products divided by the total number of values will be the value of the mean.
309084
The formula for standard deviation is sqrt([sample size][probability of success](1-[probability of success])). To find the sample size from the mean and success rate, you divide the mean by the success rate. If mean=10 and success=0.2, you do 10/0.2 to get your sample size, or 50 in this case.
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['Find the mean of the set of data.', 'Subtract each number from the mean.', 'Square the result.', 'Add the results together.']
457502
The Sampling Distribution of the Sample Mean. If repeated random samples of a given size n are taken from a population of values for a quantitative variable, where the population mean is μ (mu) and the population standard deviation is σ (sigma) then the mean of all sample means (x-bars) is population mean μ (mu).
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['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.']
366720
Count the number of observations that were used to generate the standard error of the mean. This number is the sample size. Multiply the square of the standard error (calculated previously) by the sample size (calculated previously). The result is the variance of the sample.
2963
Step 1: Calculate the mean (Total of all samples divided by the number of samples). Step 2: Calculate each measurement's deviation from the mean (Mean minus the individual measurement). Step 3: Square each deviation from mean. Squared negatives become positive.
6927
['Mean of Sample is the same as the mean of the population.', 'The standard deviation which is calculated is the same as the standard deviation of the population divided by the square root of the sample size.']
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Calculating Standard Error of the Mean 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.
250645
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.
227955
['Identify a sample statistic. Choose the statistic (e.g, sample mean, sample proportion) that you will use to estimate a population parameter.', 'Select a confidence level. ... ', 'Find the margin of error. ... ', 'Specify the confidence interval.']
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['Summary. ... ', 'Get the standard deviation in a sample.', 'Estimated standard deviation.', '=STDEV (number1, [number2], ...)', 'number1 - First number or reference in the sample. ... ', 'The STDEV function calculates the standard deviation for a sample set of data.']
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['RSD = Relative standard deviation.', 'S = Standard deviation.', 'x¯ = Mean of the data.']
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['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.']
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['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).']
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The Mean from a Frequency Table. It is easy to calculate the Mean: Add up all the numbers, then divide by how many numbers there are.
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['Calculate the mean (x̅) of a set of data\u200b', 'Subtract the mean from each point of data to determine (x-x̅). ... ', 'Square each of the resulting numbers to determine (x-x̅)^2. ... ', 'Add the values from the previous step together to get ∑(x-x̅)^2.']