COMM 2002 Lecture Notes - Sampling Distribution, Normal Distribution, Standard Deviation
Document Summary
Allows us to estimate how close our sample statistics are to the actual population values. We use what we know about the normal curve. 68 percent of all cases fall between + & - 1 sd. 95 percent of all cases fall between + & - 2 sd. 99 percent of all cases fall between + & - 3 sd. A sampling distribution is a repeated drawing of samples would produce a normal curve of samples. This distribution would have a mean and a standard deviation. Grand mean: mean of means of several subsamples. We don"t have all samples, we only have one. We know the mean of one sample will not be exactly the same as the population mean but it will fall somewhere on the normal curve of the sampling distribution. Standard error: standard deviation of the sampling distribution.