Marcos had 15 coins in nickels and quarters. he had 3 more quarters than nickels. he wrote a system of equations to represent this situation, letting x represent the number of nickels and y represent the number of quarters. then he solved the system by graphing. what is the solution ?

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