For her evidence-based practice (EBP) unit project, Zoey is reviewing a research study on preventing nosocomial infections. She is reviewing a bell-shaped curve that is presented in a data table in the study. She notes that the standard deviation is small based on the fact that the bell-shaped curve is steep. She knows that a standard deviation describes: (Select all that apply.) Every value in a distribution. The average of all variants in a sample. The highest score minus the lowest score in a deviation. All of the values divided by the number of participants. The average of deviations from the mean