The pH scale for acidity is defined by pH = − log 10 [ H + ] where [ H + ] is the concentration of hydrogen ions measured in moles per liter (M). (A) The pH of pure water is 7.0. Calculate the concentration of hydrogen ions in moles per liter (M).
(B) The pH of rain water is 5.5. Calculate the concentration of hydrogen ions in moles per liter (M).

1. why is a frequency distribution useful? it allows researchers to see the "shape" of the data. it tells researchers how often the mean occurs in a set of data. it can visually identify the mean. it ignores outliers. 2. the is defined by its mean and standard deviation alone. normal distribution frequency distribution median distribution marginal distribution 3. approximately % of the data in a given sample falls within three standard deviations of the mean if it is normally distributed. 95 68 34 99 4. a data set is said to be if the mean of the data is greater than the median of the data. normally distributed frequency distributed right-skewed left-skewed