A sample of size 100.
Standard deviation is the square root of the variance. Since you stated the variance is 4, the standard deviation is 2.
See the related links on how to calculate standard deviation. If there are more than a dozen data points, it is tedious to calculate by hand. Use excel or an online calculator. To get 2 standard deviations, multiply the calculated std deviation by 2.
The z score is (1650-1500)/150 = 150/150 = 1
The standard deviation provides in indication of what proportion of the entire distribution of the sample falls within a certain distance from the mean or average for that sample. If your data falls on a normal (or bell shaped) distribution, a SD of 1 indicates that about 68% of your data points (scores or whatever else) fall within 1 point (plus or minus) of the average (mean) of the data, and 95% fall within 2 points.
Variance is standard deviation squared. If standard deviation can be zero then the variance can obviously be zero because zero squared is still zero. The standard deviation is equal to the sum of the squares of each data point in your data set minus the mean, all that over n. The idea is that if all of your data points are the same then the mean will be the same as every data point. If the mean is the equal to every data point then the square of each point minus the mean would be zero. All of the squared values added up would still be zero. And zero divided by n is still zero. In this case the standard deviation would be zero. Short story short: if all of the points in a data set are equal than the variance will be zero. Yes the variance can be zero.
The standard deviation is a measure of how spread out the numbers are. Three points is needed to calculate a statistically valid meaningful standard deviation.
To calculate the standard deviation of a portfolio in Excel, you can use the STDEV.P function. This function calculates the standard deviation based on the entire population of data points in your portfolio. Simply input the range of values representing the returns of your portfolio into the function to get the standard deviation.
Standard deviation is the square root of the variance. Since you stated the variance is 4, the standard deviation is 2.
No. A small standard deviation with a large mean will yield points further from the mean than a large standard deviation of a small mean. Standard deviation is best thought of as spread or dispersion.
It is 15 points.
This would increase the mean by 6 points but would not change the standard deviation.
A standard deviation of zero means that all the data points are the same value.
There are two points of infection (the points where the curvature changes its direction) which lie at a distance of one standard deviation above mean and one standard deviation below mean.
In statistical analysis, the value of sigma () can be determined by calculating the standard deviation of a set of data points. The standard deviation measures the dispersion or spread of the data around the mean. A smaller standard deviation indicates that the data points are closer to the mean, while a larger standard deviation indicates greater variability. Sigma is often used to represent the standard deviation in statistical formulas and calculations.
Standard deviation shows how much variation there is from the "average" (mean). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values.
Yes, a standard deviation of 4.34 can be correct. Standard deviation is a measure of dispersion or variability in a data set. It represents the average amount by which individual data points deviate from the mean. Therefore, a standard deviation of 4.34 simply indicates that there is some variability in the data, with data points on average deviating by 4.34 units from the mean.
The mean of a distribution is a measure of central tendency, representing the average value of the data points. In this case, the mean is 2.89. The standard deviation, which measures the dispersion of data points around the mean, is missing from the question. The standard deviation provides information about the spread of data points and how closely they cluster around the mean.