nessa said:Homework Statement
In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizen are chosen, what is the standard deviation of the number favoring the substation?:yuck:
Homework Equations
I know that my mean is 15 and the probiblilty is 80 but how do I get the standard deviation.
The Attempt at a Solution
Mean is a measure of central tendency that represents the average value of a dataset, while standard deviation measures the spread or variability of the data around the mean. In other words, mean tells us where the data is centered, while standard deviation tells us how far the data points are from the mean.
To calculate the mean, add up all the values in the dataset and divide by the total number of values. For example, if we have the values 3, 5, and 7, the mean would be (3+5+7)/3 = 5. To calculate the standard deviation, first find the mean, then subtract the mean from each data point, square the differences, add them together, divide by the total number of values, and finally take the square root of the result. This may sound complicated, but it is easily done using a calculator or a spreadsheet program.
Mean and standard deviation are important descriptive statistics that help us understand the characteristics of a dataset. They provide information about the central tendency and variability of the data, which can be used to make comparisons between different groups or to identify outliers or unusual data points.
No, mean and standard deviation are not suitable for predicting future data. They are only descriptive statistics that summarize the characteristics of a given dataset. To make predictions, other statistical methods such as regression analysis or time series analysis should be used.
The larger the sample size, the more reliable the mean and standard deviation will be. With a larger sample size, the mean and standard deviation will better represent the true characteristics of the population. As the sample size decreases, there is a greater chance of sampling error, which can lead to inaccurate mean and standard deviation values.