if want to find population mean knowing the sample mean sample variance etc.

In order to find the population mean from the sample mean, sample variance and other data, you would need to apply the formula for population mean. The formula is population mean = (sample mean x sample size) + (sample variance x population size). This formula requires knowledge of the population size, which can be estimated using other available data. Once this information is obtained, you can then use the formula to calculate the population mean.